A vane structure and fan

Abstract

This application provides a stator blade structure and a fan. A first-stage stator blade and a second-stage stator blade are connected in series in the same duct. The first-stage stator blade is located at the duct inlet, and the second-stage stator blade is located at the duct outlet. The first blade root of the first-stage stator blade is connected to the hub, and the first blade tip of the first-stage stator blade is connected to the rim. The second blade root of the second-stage stator blade is connected to the hub, and the second blade tip of the second-stage stator blade is connected to the rim. At any point with the same diameter, the distance between the outlet apex of the first-stage stator blade and the inlet apex of the second-stage stator blade satisfies a first value range. Maintaining a certain distance between the first-stage and second-stage stator blades allows for a smooth airflow transition between them. Because of the use of two-stage stator blades, each stage has a shorter chord length, which helps delay stalling under high pressure. The use of two-stage stator blades also simplifies mold manufacturing and reduces costs.

Description

Technical Field

[0001] This application relates to the field of fans, specifically to a stator blade structure and a fan. Background Technology

[0002] With the development of information and electronic technology, people increasingly require speed and accuracy in data processing. The faster the product speed, the greater the heat flux density, and the more stringent the heat dissipation requirements. Fans are the main heat dissipation components in electronic products, and their performance directly determines the performance of a product. Moreover, electronic products are becoming smaller, but the internal electronic components are becoming more and more densely packed, which greatly increases air resistance. Ordinary axial fans cannot match such high-pressure scenarios. If they work in such scenarios, efficiency and noise will increase significantly, and they may not even be able to meet the heat dissipation requirements. Therefore, high-pressure, high-efficiency, and quiet fans have become the first choice for product thermal design. In addition, in the context of increasingly scarce energy, energy efficiency has also become an essential indicator to consider.

[0003] Traditional axial flow fans used for high pressure are generally equipped with outlet stator vanes. In fan theory, fan stall starts from the suction side. Increasing the chord length of the stator vanes can delay stall, but increasing the chord length will bring the following problems:

[0004] 1. If the chord length of the stationary blade is too long, it will not only fail to delay stall and increase pressure, but will also cause the pressure of the fan to decrease instead of increase due to friction loss between the blades, especially in high-pressure situations.

[0005] 2. The chord length of the stationary blade is too long, making it very difficult to achieve in engineering molds, resulting in high finished product costs. Summary of the Invention

[0006] This application provides a stator blade structure and a fan to solve at least one of the problems pointed out in the background art.

[0007] The first aspect of this application provides a stator blade structure, including: a first-stage stator blade, a second-stage stator blade, a hub, and a rim;

[0008] The first-stage and second-stage stationary blades are connected in series in the same duct, with the first-stage stationary blades located at the air inlet of the duct and the second-stage stationary blades located at the air outlet of the duct.

[0009] The root of the first stage stationary blade is connected to the hub, the tip of the first stage stationary blade is connected to the rim, the root of the second stage stationary blade is connected to the hub, and the tip of the second stage stationary blade is connected to the rim.

[0010] Taking any position with the same diameter, the distance between the exit vertex of the first-stage stator blade and the inlet vertex of the second-stage stator blade satisfies the first value range.

[0011] Based on the first aspect of the embodiments of this application, in the first implementation of the first aspect of the embodiments of this application, the first root installation angle of the first stage stationary blade is greater than the first tip installation angle of the first stage stationary blade, and the difference between the first root installation angle and the first tip installation angle is less than a first preset difference.

[0012] Based on the first aspect of the embodiments of this application or the first implementation of the first aspect, in the second implementation of the first aspect of the embodiments of this application, the installation angle of the first stage stator decreases as the diameter increases.

[0013] Based on any one of the first aspect, the first implementation method and the second implementation method of the embodiments of this application, in the third implementation method of the first aspect of the embodiments of this application, the installation angle of the first stage stator blade changes uniformly with the diameter.

[0014] Based on any one of the first to third implementations of the embodiments of this application, in the fourth implementation of the first aspect of this application, the first preset difference is 10 degrees.

[0015] Based on any one of the first to fourth implementations of the embodiments of this application, in the fifth implementation of the first aspect of the embodiments of this application, the second root installation angle of the second stage stationary blade is smaller than the second tip installation angle of the second stage stationary blade.

[0016] Based on any one of the first to fifth implementations of the embodiments of this application, in the sixth implementation of the first aspect of this application, the installation angle of the second stage stator increases as the diameter increases.

[0017] Based on any one of the first to sixth implementations of the embodiments of this application, in the seventh implementation of the first aspect of this application, the installation angle of the second-stage stationary blade changes uniformly with the diameter.

[0018] Based on any one of the first to seventh implementations of the embodiments of this application, in the eighth implementation of the first aspect of the embodiments of this application, the difference between the first leaf root installation angle and the first leaf tip installation angle is greater than the difference between the second leaf tip installation angle and the second leaf root installation angle.

[0019] Based on any one of the first to eighth implementations of the embodiments of this application, in the ninth implementation of the first aspect of the embodiments of this application, the first value ranges from 1 mm to 2 mm.

[0020] Based on any one of the first to ninth implementations of the embodiments of this application, in the tenth implementation of the first aspect of this application, the blade shape of the stationary blade is an airfoil.

[0021] A first aspect of this application provides a fan, including: a motor, moving blades, and the stationary blade structure described in the first aspect.

[0022] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0023] In this embodiment, the stator structure includes two stages of stator blades—a first-stage stator blade and a second-stage stator blade. These two stages are connected in series within the duct, and a certain distance is maintained between them. Specifically, at the same diameter position, the distance between the outlet apex of the first-stage stator blade and the inlet apex of the second-stage stator blade satisfies a first value range, allowing for a smooth airflow transition between the two stages. Because of the two-stage stator blades, each stage has a shorter chord length, which helps delay stalling under high pressure, resulting in a smoother airflow field, reduced friction, lower noise, and improved efficiency. Furthermore, the shorter chord length of each stage simplifies mold fabrication and reduces costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the installation angle of the existing stationary blade structure;

[0025] Figure 2 This is a schematic diagram of the installation angle of the first stage stationary blade in an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the installation angle of the second-stage stationary blade in an embodiment of this application;

[0027] Figure 4 This is a fluid distribution diagram of an existing stator blade structure;

[0028] Figure 5 This is a fluid distribution diagram of the stator blade structure in an embodiment of this application;

[0029] Figure 6 This is a front view of an existing stator blade structure;

[0030] Figure 7 This is a front view of the stationary blade structure according to an embodiment of this application;

[0031] Figure 8 These are data graphs from a comparative experiment between existing blade structures and the blade structures described in this application.

[0032] Figure label:

[0033] 1-First stage stationary blade; 2-Second stage stationary blade; 3-Hub; 4-Wheel rim; 5-Reference surface; 6-Reference ray; 7-Hub section; 8-Wheel rim section; 9-Intermediate position section; 10-Pressure surface; 11-Suction surface; 12-First pressure surface; 13-First suction surface; 14-Second pressure surface; 15-Second suction surface; 16-Efficiency curve; 17-Pressure curve. Detailed Implementation

[0034] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] According to fan theory, when a fan operates in a high-pressure zone, the pressure distribution on the stator blades becomes highly disordered. Especially on the suction surface, due to the reverse pressure gradient, the airflow begins to separate along the direction of the incoming flow. Furthermore, along the radial direction, interference from the wakes of the moving blades causes uneven pressure distribution, resulting in low fan efficiency and high noise. The main approach of this application is to divide the primary stator blades into two stages.

[0036] This application provides a stator blade structure, including: a first-stage stator blade, a second-stage stator blade, a hub, and a rim.

[0037] The first-stage and second-stage stationary blades are connected in series in the same duct, with the first-stage stationary blades located at the duct inlet and the second-stage stationary blades located at the duct outlet.

[0038] The first-stage and second-stage stationary blades are connected in series, meaning they are arranged coaxially. When airflow passes through the duct, it first passes through the first-stage stationary blades and then through the second-stage stationary blades.

[0039] The root of the first stage stationary blade is connected to the hub, the tip of the first stage stationary blade is connected to the rim, the root of the second stage stationary blade is connected to the hub, and the tip of the second stage stationary blade is connected to the rim.

[0040] The leaf root and leaf tip are the two ends of the leaf in the diameter direction. The leaf root is located at the smallest diameter and the leaf tip is located at the largest diameter.

[0041] Taking any position with the same diameter, the distance between the exit vertex of the first-stage stator blade and the inlet vertex of the second-stage stator blade satisfies the first value range.

[0042] The method for measuring the distance between the exit vertex of the first-stage stator and the inlet vertex of the second-stage stator at the same diameter position is as follows: A cross-section of the stator structure is obtained by cutting a section with a cylindrical surface coaxial with the duct. The cylindrical surface is then unfolded, and a line segment is drawn on the cross-section with the exit vertex of the first-stage stator and the inlet vertex of the second-stage stator as its vertices. This line segment is the reference line segment. The length of the reference line segment is the distance between the exit vertex of the first-stage stator and the inlet vertex of the second-stage stator at the same diameter position.

[0043] It should be noted that when constructing a reference line segment, the nearest vertex of the first-level still leaf exit and the vertex of the second-level still leaf entrance should be used as the line segment vertices.

[0044] Taking any cylindrical section coaxial with the duct from the blade root to the blade tip, the distance between the exit vertex of the first-stage stator blade and the inlet vertex of the second-stage stator blade, measured at any point along the duct, satisfies the first value range. In other words, for all diameters between the hub and the rim, the distance between the exit vertex of the first-stage stator blade and the inlet vertex of the second-stage stator blade satisfies the first value range.

[0045] like Figure 5 As shown in one implementation of this application, the first value ranges from 1 mm to 2 mm.

[0046] At the same diameter position, the distance between the apex of the first-stage stator blade exit and the apex of the second-stage stator blade inlet is greater than or equal to 1 mm and less than or equal to 2 mm.

[0047] The installation angle will be explained below. The measurement method for the installation angle is as follows: A section of the stator blade is cut from a cylindrical surface coaxial with the duct, and the cylindrical surface is unfolded. A ray is drawn from the stator blade outlet vertex to the stator blade inlet vertex on the section to obtain a reference ray. Using the vertical plane of the duct axis as the reference plane, the angle between the reference ray and the reference plane is the installation angle. The stator blade outlet vertex is the point on the section that is closest to the air outlet, and the stator blade inlet vertex is the point on the section that is closest to the air inlet. Because the stator blade is curved, using cylindrical surfaces of different diameters to cut the stator blade allows us to obtain the installation angle at different positions.

[0048] The stationary blade is cut from a cylindrical surface with the same diameter as the maximum diameter of the hub, and the resulting installation angle is the blade root installation angle.

[0049] The stationary blade is cut from a cylindrical surface with the same diameter as the inner diameter of the rim, and the resulting installation angle is the blade tip installation angle.

[0050] It should be noted that when drawing the reference ray, the apex of the stator blade exit and the apex of the stator blade inlet can be omitted, and other points that are easy to measure can be selected; there are no specific restrictions.

[0051] like Figure 2 As shown, in one implementation of this application embodiment, the first root installation angle of the first stage stationary blade is greater than the first tip installation angle of the first stage stationary blade, and the difference between the first root installation angle and the first tip installation angle is less than a first preset difference.

[0052] Generally, in a stator blade structure with only one stage, the difference between the blade root installation angle and the blade tip installation angle is a first preset difference. That is to say, the difference between the first blade root installation angle and the first blade tip installation angle in the embodiment of this application is less than the corresponding difference in a stator blade structure with only one stage.

[0053] In one implementation of this application, the first preset difference is 10 degrees. The difference between the first blade root installation angle and the first blade tip installation angle is less than 10 degrees.

[0054] In one implementation of this application, the installation angle of the first-stage stator decreases as the diameter increases.

[0055] The installation angle of the first-stage stationary blade decreases continuously from the blade root to the blade tip. This decrease can be uniform or non-uniform. The installation angle of the first-stage stationary blade is negatively correlated with the diameter at the location where the installation angle is measured.

[0056] In one implementation of this application, the installation angle of the first-stage stator blade changes uniformly with the diameter.

[0057] The installation angle of the first-stage stationary blade gradually and uniformly decreases from the blade root to the blade tip. The installation angle of the first-stage stationary blade is inversely proportional to the diameter at the measurement location.

[0058] like Figure 3 As shown, in one implementation of this application embodiment, the second root installation angle of the second stage stationary blade is smaller than the second tip installation angle of the second stage stationary blade.

[0059] In one implementation of this application, the installation angle of the second-stage stator increases as the diameter increases.

[0060] The installation angle of the second-stage stationary blade decreases continuously from the blade root to the blade tip. This decrease can be uniform or non-uniform. The installation angle of the second-stage stationary blade is positively correlated with the diameter at which the installation angle is measured. Therefore, in the diametrical direction, the second-stage stationary blade and the first-stage stationary blade exhibit opposite trends in their installation angle changes.

[0061] In one implementation of this application, the installation angle of the second-stage stator blade changes uniformly with the diameter.

[0062] The installation angle of the second-stage stator blades gradually decreases uniformly from the blade root to the blade tip. The installation angle of the second-stage stator blades is proportional to the diameter at the position where the installation angle is measured.

[0063] As Figures 2 to 3 shown, in one implementation of the embodiment of the present application, the difference between the first blade root installation angle and the first blade tip installation angle is greater than the difference between the second blade tip installation angle and the second blade root installation angle.

[0064] The difference between the first blade root installation angle and the first blade tip installation angle is greater than 0, and the difference between the second blade tip installation angle and the second blade root installation angle is greater than 0.

[0065] The change rate of the installation angle of the first-stage stator blades in the diameter direction is greater than that of the second-stage stator blades.

[0066] As Figures 2 to 3 shown, in one implementation of the embodiment of the present application, the blade profile of the stator blade is an airfoil.

[0067] In one implementation of the embodiment of the present application, the stator blade structure can be integrally injection molded.

[0068] The embodiment of the present application provides a fan, including: a motor, a rotor blade, and a stator blade structure as Figure 2 , Figure 3 and Figure 7 shown.

[0069] By analyzing the real flow field inside the fan, the pressure and flow field distribution of the stator blades of the fan are obtained. By changing the stator blades from a one-piece type to a two-piece type, the pressure distribution of the two-stage stator blades is improved, thereby improving the overall flow field of the fan, enhancing the performance, and reducing the noise.

[0070] To further illustrate the present application, a comparison between the prior art and the embodiment of the present application is given.

[0071] According to the fan theory, the airflow coming out of the impeller is different from the hub to the rim direction. As Figures 1 to 3 shown, for the prior art, the installation angle of the first-stage stator blades gradually decreases from the hub to the frame wall (B1>B2>B3), while for the stator blade structure of the embodiment of the present application, the installation angle of the first-stage stator blades gradually decreases from the hub to the rim (B11>B12>B13), but the difference between the two is less than that of the prior art stator blade (B11-B13<B1-B3), and the installation angle of the second-stage stator blades slightly increases from the rim to the frame wall (B21<B22<B23).

[0072] B1 is the blade root installation angle of the prior art, B2 is the installation angle at the middle position of the prior art, and B3 is the blade tip installation angle of the prior art. The middle position refers to the position at the midpoint between the blade tip and the blade root.

[0073] B11 is the blade root installation angle of the first-stage stationary blade, B12 is the installation angle at the middle position of the first-stage stationary blade, and B13 is the blade tip installation angle of the first-stage stationary blade.

[0074] B21 is the blade root installation angle of the second-stage stationary blade, B22 is the installation angle at the middle position of the second-stage stationary blade, and B23 is the blade tip installation angle of the second-stage stationary blade.

[0075] The hub section refers to the cross-section obtained by cutting the stationary blade using a cylindrical surface with the same diameter as the maximum diameter of the hub.

[0076] The intermediate section refers to the section obtained by cutting the stationary blade with a cylindrical surface passing through the intermediate position.

[0077] The rim section refers to the cross section obtained by cutting the stationary blade using a cylindrical surface with the same diameter as the inner diameter of the rim.

[0078] The airflow direction indicates the direction of airflow within the duct.

[0079] like Figures 4 to 5 As shown, in this embodiment of the application, a gap of 1mm to 2mm is maintained between the outlet of the first stage stator blade and the inlet of the second stage stator blade. When the fan is working in the high-pressure zone, the high-pressure fluid on the first pressure surface of the first stage stator blade can flow into the second suction surface of the second stage stator blade through the gap, thereby increasing the fluid kinetic energy on the suction surface of the second stage stator blade and thus delaying the stall state of the second stage stator blade. Compared with the prior art, this improves the blockage of the stator blade flow channel.

[0080] The existing stator blades have a pressure surface and a suction surface, and the airflow exhibits a stall state at the end of the suction surface.

[0081] In this embodiment, the first stage stationary blade has a first pressure surface and a first suction surface, the second stage stationary blade has a second pressure surface and a second suction surface, and the airflow at the end of the second suction surface exhibits a stall state.

[0082] like Figures 6 to 7 As shown, compared with the prior art, the inlet edge shapes of the first-stage stator and the second-stage stator in this application embodiment are different. After performing computational fluid dynamics (CFD) analysis, the inlet edge of the first-stage stator is designed based on the outlet pressure distribution of the stator, while the inlet edge shape of the second-stage stator is designed based on the outlet pressure distribution of the first-stage stator. The incoming flow fields of the two are significantly different, so the inlet shapes of the two are not consistent.

[0083] To verify the effectiveness of the embodiments of this application, the experimental results are given below:

[0084] like Figure 8As shown in the figure, the original model uses only a single-stage stator blade, while the improved model, as described in this application embodiment, provides a stator blade structure. The horizontal axis in the figure represents gas flow rate in cubic feet per minute (CFM); the vertical axis on the left represents pressure in millimeters of water column (mmH2O); and the vertical axis on the right represents efficiency in percentage (%). In the experiment, the fan blades rotated at a speed of 4500 revolutions per minute (rpm). The two curves passing through the origin in the figure are efficiency curves, and the two curves that monotonically decrease with increasing gas flow rate are pressure curves.

[0085] This application's embodiment utilizes a multi-stage stator blade design method, which delays fan stall under high pressure, resulting in smoother fan flow. This improves fan efficiency by 5% in the high-pressure zone and reduces noise from 53.5 dBA to 52 dBA, a reduction of 1.5 dBA. The high-pressure zone refers to the area between 10 mmH2O and 20 mmH2O.

[0086] By studying the flow field of the stator blades, the traditional single-segment stator blade design was changed to a multi-segment design, which improved the pressure distribution on the stator blades, delayed stator blade stall, improved fan energy efficiency, and reduced fan noise. The stator blade structure of this application embodiment can be used for the same type of moving and stator blade fans of different sizes.

[0087] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A stationary blade structure, characterized in that, include: First-stage stationary vane, second-stage stationary vane, hub, rim; The first-stage and second-stage stationary blades are connected in series in the same duct, with the first-stage stationary blades located at the air inlet of the duct and the second-stage stationary blades located at the air outlet of the duct. The root of the first stage stationary blade is connected to the hub, the tip of the first stage stationary blade is connected to the rim, the root of the second stage stationary blade is connected to the hub, and the tip of the second stage stationary blade is connected to the rim. Taking any position with the same diameter, the distance between the exit vertex of the first-stage stator blade and the inlet vertex of the second-stage stator blade satisfies the first value range. The first root installation angle of the first stage stationary blade is greater than the first tip installation angle of the first stage stationary blade, the difference between the first root installation angle and the first tip installation angle is less than the first preset difference, and the installation angle of the first stage stationary blade decreases as the diameter increases. The second root installation angle of the second stage stationary blade is smaller than the second tip installation angle of the second stage stationary blade, and the installation angle of the second stage stationary blade increases with the increase of the diameter. The rate of change of the installation angle of the first-stage stator in the diameter direction is greater than that of the second-stage stator in the diameter direction.

2. The stationary blade structure according to claim 1, characterized in that, The installation angle of the first-stage stationary blade changes uniformly with the diameter.

3. The stationary blade structure according to claim 1, characterized in that, The first preset difference is 10 degrees.

4. The stationary blade structure according to claim 1, characterized in that, The installation angle of the second-stage stationary blade changes uniformly with the diameter.

5. The stationary blade structure according to claim 1, characterized in that, The difference between the first blade root installation angle and the first blade tip installation angle is greater than the difference between the second blade tip installation angle and the second blade root installation angle.

6. The stationary blade structure according to claim 1, characterized in that, The first value range is 1 mm to 2 mm.

7. The stationary blade structure according to claim 1, characterized in that, The leaves of the Jingye plant are wing-shaped.

8. A fan, characterized in that, include: The motor, the moving blade, and the stationary blade structure as described in any one of claims 1 to 7.

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