Cross-flow fan blade tail edge sawtooth structure and cross-flow wind wheel applying same

Abstract

The invention relates to the technical field of cross-flow wind wheels, in particular to a cross-flow fan blade tail edge sawtooth structure and a cross-flow wind wheel applying the cross-flow fan blade tail edge sawtooth structure. The sawtooth structure comprises a fan blade body, and the peripheral contour of the fan blade body is defined by a fan blade root edge, a fan blade tail edge, a fan blade top edge and a fan blade front edge; the fan blade main body is provided with a pressure surface and a suction surface, the pressure surface and the suction surface are oppositely arranged, the pressure surface is concavely arranged towards the suction surface, so that the suction surface is convexly arranged, and the section shape of the pressure surface, the section shape of the suction surface, the fan blade root edge and the fan blade top edge are arranged in an arc shape; a plurality of notches are formed in the tail edge of the fan blade in an inwards-concave mode, and the adjacent notches are different. By means of the innovative structural design, noise is effectively reduced, and meanwhile it is guaranteed that the core aerodynamic performance of the fan blade is stable.

Description

Technical Field

[0001] This invention relates to the field of cross-flow wind turbine technology, and in particular to a cross-flow wind turbine blade trailing edge serrated structure and a cross-flow wind turbine using the same. Background Technology

[0002] Cross-flow fan blades are widely used in air conditioning, ventilation equipment, and other fields, and their performance directly affects the effectiveness of the equipment. Traditional cross-flow fan blades often employ a smooth, straight trailing edge structure or a single-size cut design, which has obvious performance defects. A smooth trailing edge easily forms continuous, large-scale shedding vortices under the action of airflow, resulting in sharp aerodynamic noise and affecting the user experience; while a single-size cut is difficult to adapt to the suppression requirements of vortices of different sizes, resulting in uneven noise reduction effects, and may also adversely affect the aerodynamic performance of the fan blade, making it difficult to achieve a good balance between noise control and aerodynamic performance. Summary of the Invention

[0003] One objective of this invention is to propose a sawtooth structure at the trailing edge of a cross-flow fan blade, which, through innovative structural design, effectively reduces noise while ensuring the stability of the core aerodynamic performance of the fan blade.

[0004] Another object of the present invention is to provide a cross-flow impeller that uses a cross-flow impeller trailing edge serrated structure as described above.

[0005] To achieve this objective, the present invention adopts the following technical solution: A cross-flow fan blade with a serrated trailing edge structure includes a fan blade body, the peripheral contour of which is formed by the fan blade root edge, the fan blade trailing edge, the fan blade top edge and the fan blade leading edge. The main body of the fan blade has a pressure surface and a suction surface, which are arranged opposite to each other. The pressure surface is recessed towards the suction surface, so that the suction surface is convex. The cross-sectional shape of the pressure surface, the cross-sectional shape of the suction surface, the root edge of the fan blade, and the top edge of the fan blade are all arc-shaped. The blade has multiple incisions recessed at its trailing edge, and adjacent incisions are not identical.

[0006] Preferably, a cutting plane is made through the top edge of the blade to the suction surface. Under the projection of the cutting plane, the root edge, tail edge, top edge, and leading edge of the blade sequentially form a root edge profile, a tail edge profile, a top edge profile, and a leading edge profile, and the cut forms a cut profile. The root edge profile and the top edge profile of the blade are arranged in parallel, the trailing edge profile and the leading edge profile of the blade are arranged in parallel, and the shape of the cut profile includes at least one of triangle, rectangle or trapezoid.

[0007] Preferably, the vertical distance between the root edge profile of the wind turbine blade and the tip edge profile of the wind turbine blade is defined as the axial length L of the wind turbine blade; The arrangement order of the multiple cuts is defined as starting from the root edge of the blade and ending at the tip edge of the blade; The vertical distance between the center of the cut-out profile at the first end and the root edge profile of the blade is defined as l3; The vertical distance between the center of the cutout profile at the end and the top edge profile of the blade is defined as l1; Among them, l1≥3.5%L, l3≥11%L.

[0008] Preferably, one of the cuts is defined as the first cut, and the cut adjacent to the first cut is the second cut; Define the center-to-center distance between the first incision and the second incision as l2; Among them, l2≥8%L.

[0009] Preferably, the depth of the first incision is defined as h1, and the depth of the second incision is defined as h2; Where h2 = (0.75~1.25)h1, h1 ≤ 14%H.

[0010] Preferably, the opening angle of the first cut is defined as θ1, and the opening angle of the second cut is defined as θ2; Where 0°≤θ1≤90°, 0°≤θ2≤90°.

[0011] Preferably, the bottom width of the first cut is defined as a1, and the bottom width of the second cut is defined as a2; Where 0≤a2≤a1≤6%L.

[0012] A cross-flow wind turbine includes multiple covers and multiple blade sections, with one blade section disposed between two adjacent covers; The blade section includes multiple blade bodies, which are arranged around the center of the cover. The trailing edge of the blade body is provided with a serrated structure as described above. The root edge of the wind blade body is fixedly installed to the cover body through the small end mounting part, and the top edge of the wind blade body is fixedly installed to the cover body through the large end mounting part. Under the projection of the tangent plane, the vertical distance between the leading edge profile and the trailing edge profile of the wind turbine blade is defined as the radial length H of the wind turbine blade; The diameter of the cover is defined as the diameter D of the impeller; Among them, 9%D≤H≤13%D.

[0013] Preferably, the straight line connecting the centers of the plurality of covers is defined as the rotation axis of the cross-flow fan; In each blade section, the serrated structures on two adjacent blade bodies are projected at the same position on the rotation axis of the blade body, and the cuts on multiple blade bodies are arranged in a ring. The circumferential angle α between adjacent blade sections about the rotation axis of the cross-flow wind turbine is defined as the misalignment angle; Where -10°≤α≤10°.

[0014] Preferably, in each of the blade portions, the center of the cover is defined as the center O, the center corresponding to the root edge of the blade body is defined as O1, and the center corresponding to the top edge of the blade body is defined as O2. Define ∠O1OO2, formed by centers O1, O, and O2, as the blade tilt angle β; Where β = γ × L, and γ ≤ 0.08° / mm, γ is the blade tilt coefficient.

[0015] One of the above technical solutions has the following beneficial effects: (1) The arc design of the pressure surface, suction surface, root edge of the blade, and leading edge of the blade effectively optimizes the aerodynamic profile of the blade, reduces the adhesion loss of airflow on the blade surface, improves the basic aerodynamic performance of the blade, and ensures the output of air volume and air pressure. (2) The setting of multiple different cuts on the trailing edge of the wind turbine blade changes the traditional airflow separation mode of the trailing edge of the wind turbine blade from a structural point of view, avoids the generation of continuous large-scale vortices, suppresses the formation of sharp aerodynamic noise from the source, and significantly improves the sound quality. (3) Different layouts of different cuts are adapted to the airflow separation characteristics of different regions of the trailing edge. Compared with a single-size cut, the noise reduction effect is more uniform and comprehensive. At the same time, it avoids the excessive influence of a single cut on aerodynamic performance and achieves a preliminary balance between noise reduction and aerodynamic performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a cross-flow fan blade trailing edge serrated structure. Figure 2 A tangential projection of the trailing edge sawtooth structure of a cross-flow fan blade Figure 1 ; Figure 3 A tangential projection of the trailing edge sawtooth structure of a cross-flow fan blade Figure 2 ; Figure 4 This is a schematic diagram of the structure of the cross-flow fan blades in a cross-flow fan rotor; Figure 5 This is a schematic diagram of a cross-flow wind turbine; Figure 6This is a side view of a cross-flow wind turbine; Figure 7 This is a schematic diagram of a cross-sectional view of a cross-flow wind turbine; Figure 8 yes Figure 7 Simplified diagram; In the attached diagram: 1. Main body of the wind turbine blade; 11. Root edge of the wind turbine blade; 12. Tail edge of the wind turbine blade; 13. Top edge of the wind turbine blade; 14. Leading edge of the wind turbine blade; 15. Pressure surface; 16. Suction surface; Incision 2, first incision 21, second incision 22; 3. Cover body; 4. Blade section; 5. Small head mounting section; 6. Large head mounting section. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "left," "right," "vertical," "level," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] A cross-flow fan blade with a serrated trailing edge includes a fan blade body 1, the peripheral contour of which is formed by a fan blade root edge 11, a fan blade trailing edge 12, a fan blade top edge 13, and a fan blade leading edge 14. The main body of the fan blade 1 has a pressure surface 15 and a suction surface 16. The pressure surface 15 and the suction surface 16 are arranged opposite to each other. The pressure surface 15 is recessed towards the suction surface 16 so that the suction surface 16 is convex. The cross-sectional shape of the pressure surface 15, the cross-sectional shape of the suction surface 16, the root edge 11 of the fan blade, and the top edge 13 of the fan blade are arranged in an arc. The trailing edge 12 of the fan blade has a plurality of cuts 2 recessed inward, and adjacent cuts 2 are not the same.

[0022] like Figure 1-3 As shown, this technical solution defines the core components and basic form of the sawtooth structure at the trailing edge of the cross-flow fan blade: the main body 1 of the fan blade is enclosed by the root edge 11, the trailing edge 12, the top edge 13, and the leading edge 14 to form a complete peripheral contour. The pressure surface 15 is recessed towards the suction surface 16, and the suction surface 16 is correspondingly convex. Combined with the arc structure of the root edge 11 and the top edge 13, the airflow can flow smoothly along the blade surface, reducing the initial flow disturbance. The multiple adjacent and different cuts 2 recessed in the trailing edge 12 of the fan blade break the structural limitations of the traditional smooth trailing edge or single-size cut 2. Through the differentiated layout of cuts 2 of different sizes, the airflow that is about to separate at the trailing edge 12 of the fan blade is divided, which destroys the formation conditions of large-scale vortices and decomposes the vortex into multiple small-scale vortices, reducing the energy release intensity when the vortex falls off.

[0023] To further explain, a tangent plane is drawn through the top edge 13 of the wind blade to the suction surface 16. Under the projection of the tangent plane, the root edge 11, the trailing edge 12, the top edge 13, and the leading edge 14 of the wind blade sequentially form the root edge profile, the trailing edge profile, the top edge profile, and the leading edge profile, and the cut 2 forms the cut profile. The root edge profile and the top edge profile of the blade are arranged in parallel, the trailing edge profile and the leading edge profile of the blade are arranged in parallel, and the shape of the cut profile includes at least one of triangle, rectangle or trapezoid.

[0024] like Figure 2 As shown, by using the tangent plane of the suction surface 16 through the top edge 13 of the blade, the contours of each blade and the cut 2 are projected as profiles, clarifying the projection relationship that the root edge profile of the blade is parallel to the top edge profile of the blade, and the trailing edge profile of the blade is parallel to the leading edge profile of the blade. This ensures the consistency of the aerodynamic profile of the blade body 1 in the axial and radial directions, keeps the flow pattern of the airflow uniform throughout the entire length of the blade body 1, and reduces local flow turbulence. The cut profile is limited to at least one of triangle, rectangle, or trapezoid. Both shapes of cut 2 have regular geometric structures, which are easy to process and manufacture. At the same time, the cutting angle and range of the airflow are precisely controlled by the cut 2. The rectangular cut 2 can achieve vertical division of the airflow, while the trapezoidal cut 2 can guide the direction of airflow separation according to the angle of the hypotenuse, further optimizing the vortex decomposition effect.

[0025] To further clarify, the vertical distance between the root edge profile of the wind turbine blade and the tip edge profile of the wind turbine blade is defined as the axial length L of the wind turbine blade; The arrangement order of the multiple cuts 2 is defined as starting from the root edge 11 of the wind blade and ending at the top edge 13 of the wind blade; The vertical distance between the center of the cut-out profile at the first end and the root edge profile of the blade is defined as l3; The vertical distance between the center of the cutout profile at the end and the top edge profile of the blade is defined as l1; Among them, l1≥3.5%L, l3≥11%L.

[0026] like Figure 2-3 As shown, the definitions of the axial length L (vertical distance between the root edge profile and the tip edge profile) and radial length H (vertical distance between the leading edge profile and the trailing edge profile) of the blade are clearly defined, providing a benchmark for the subsequent quantitative design of the parameters of the cut 2. The arrangement order of the cuts 2 is limited from the root edge 11 to the tip edge 13 of the blade to ensure that the cuts 2 cover the key airflow separation area of ​​the trailing edge. The vertical distance l3 between the center of the first cut 2 and the root edge profile is ≥11%L to avoid the cut 2 being too close to the installation area of ​​the root edge 11 of the blade, to prevent the formation of an airflow stagnation zone between the wall of the root edge 11 of the blade and the cut 2, and to avoid the increase in flow resistance caused by the accumulation of eddies in this area. The vertical distance l1 between the center of the last cut 2 and the tip edge profile of the blade is ≥3.5%L to prevent the cut 2 from being too close to the end of the tip edge 13 of the blade, to avoid the weakening of the blade tip edge structural strength due to improper position of the cut 2, and to avoid mutual interference between the airflow at the tip edge 13 of the blade and the cut 2.

[0027] To further explain, the cut 2 described herein is defined as the first cut 21, and the cut 2 adjacent to the first cut 21 is defined as the second cut 22; The center-to-center distance between the first cut 21 and the second cut 22 is defined as l2; Among them, l2≥8%L.

[0028] like Figure 2 As shown, two adjacent different cuts 2 are defined as the first cut 21 and the second cut 22, and the center distance between them, l2, is specified to be ≥8%L. The arrangement density of the cuts 2 is limited by the proportional relationship with the axial length L of the fan blade. This design is based on the airflow velocity and separation law, avoiding the mutual compression and blockage of airflow between adjacent cuts 2 due to the excessively dense arrangement of cuts 2. It ensures that each cut 2 can independently play its role in dividing the airflow, while reserving sufficient space for the airflow between the cuts 2 to maintain the smoothness of the airflow.

[0029] To further explain, the depth of the first cut 21 is defined as h1, and the depth of the second cut 22 is defined as h2; Where h2 = (0.75~1.25)h1, h1 ≤ 14%H.

[0030] like Figure 3 As shown, the depth h1 of the first cut 21 and the depth h2 of the second cut 22 are defined, and h2 is limited to 0.75~1.25h1. This ensures that the depths of the two adjacent cuts 2 maintain a reasonable difference, which can be adapted to the suppression requirements of vortices of different scales. The cut 2 with a larger depth can divide the larger scale vortices, and the cut 2 with a smaller depth can decompose the smaller scale vortices, so as to achieve comprehensive suppression of vortices of different scales at the trailing edge 12 of the wind turbine blade. At the same time, h1 is limited to ≤14%H to avoid excessive weakening of the trailing edge structure due to excessive depth of cut 2, to prevent insufficient strength of the wind turbine blade body 1, and to avoid the excessive depth from destroying the adhesion state of the airflow on the surface of the wind turbine blade body 1, so as to ensure that the airflow can flow normally along the surface of the wind turbine blade body 1 without generating additional flow losses.

[0031] To further explain, the opening angle of the first cut 21 is defined as θ1, and the opening angle of the second cut 22 is defined as θ2; Where 0°≤θ1≤90°, 0°≤θ2≤90°.

[0032] like Figure 3 As shown, the opening angle θ1 of the first cut 21 and the opening angle θ2 of the second cut 22 are defined, with 0°≤θ1≤90° and 0°≤θ2≤90°. The opening angle directly affects the direction in which the cut 2 guides and divides the airflow. When the opening angle is 0°, the shape of the cut profile is rectangular, vertically dividing the airflow. When the opening angle is between 0° and 90°, the shape of the cut profile is trapezoidal, and the inner wall of the cut 2 forms an inclined angle, which can guide the airflow to separate along the inclined direction, further optimizing the vortex decomposition effect. An opening angle of 90° can maximize the coverage of the airflow by the cut 2, enhancing the division capability. This limited angle range ensures that the cut 2 can effectively divide the vortex without causing a sharp increase in airflow resistance due to an excessively large angle.

[0033] To further explain, the bottom width of the first cut 21 is defined as a1, and the bottom width of the second cut 22 is defined as a2. Where 0≤a2≤a1≤6%L.

[0034] like Figure 3As shown, the bottom width a1 of the first cut 21 and the bottom width a2 of the second cut 22 are defined, with a limit of 0 ≤ a2 ≤ a1 ≤ 6%L. The size of the bottom width directly affects the contact area between the cut 2 and the airflow and the structural strength. A smaller bottom width can reduce airflow resistance, while a larger bottom width can improve structural strength and vortex segmentation effect. The limit of a2 ≤ a1 maintains the difference in bottom width between adjacent cuts 2, which, together with the difference in depth, further optimizes the suppression effect on vortices of different scales. The limit of ≤ 6%L avoids the surge in airflow resistance caused by excessively large bottom widths of a single first cut 21 and a single second cut 22, while ensuring the structural strength of the cut 2 itself and preventing deformation or breakage of the cut 2 due to excessive width.

[0035] A cross-flow wind turbine includes multiple covers 3 and multiple blade sections 4, with one blade section 4 disposed between two adjacent covers 3; The blade section 4 includes a plurality of blade bodies 1, which are arranged around the center of the cover 3. The trailing edge 12 of the blade body 1 is provided with a serrated structure as described above. The root edge 11 of the blade body 1 is fixedly installed to the cover 3 through the small end mounting part 5, and the top edge 13 of the blade body 1 is fixedly installed to the cover 3 through the large end mounting part 6. Under the projection of the tangent plane, the vertical distance between the leading edge profile and the trailing edge profile of the wind turbine blade is defined as the radial length H of the wind turbine blade; The diameter of the cover 3 is defined as the diameter D of the impeller; Among them, 9%D≤H≤13%D.

[0036] like Figure 4-8As shown, the cross-flow wind turbine consists of multiple covers 3 and blade sections 4. Blade sections 4 are arranged between adjacent covers 3, forming a modular structure that facilitates assembly and maintenance. Multiple blade bodies 1 of the blade section 4 are arranged around the center of the cover 3, forming an annular airflow channel. The serrated structure of the blade trailing edge 12 is distributed along the annularity, comprehensively dividing the trailing edge airflow in the entire circumference of the wind turbine. The blade body 1 is fixed to the corresponding cover 3 by the small end mounting part 5 and the large end mounting part 6, respectively, ensuring the firmness of the blade installation and preventing the blades from loosening or shifting when the wind turbine rotates at high speed. At the same time, it ensures the consistency of the spacing between the blades and maintains the stability of the airflow channel. Furthermore, under the projection of the tangent plane of the suction surface 16, the proportional relationship between the radial length H of the blade (the perpendicular distance between the leading edge profile and the trailing edge profile) and the diameter D of the wind turbine is clarified (9%D≤H≤13%D). This proportional design is based on the optimization of the wind turbine's aerodynamic characteristics, making the radial dimension of the blade match the overall diameter of the wind turbine, ensuring smooth airflow within the radial range of the blade. This is because if the radial length H of the wind turbine blade is too small, the blade will have low working efficiency, while if the radial length H of the wind turbine blade is too long, it will cause flow blockage between the blades.

[0037] To further explain, the straight line connecting the centers of the plurality of covers 3 is defined as the rotation axis of the cross-flow fan. In each blade section 4, the serrated structures on two adjacent blade bodies 1 are projected at the same position on the rotation axis of the blade body 1, and the cuts 2 on multiple blade bodies 1 are arranged in a ring. The circumferential angle α between adjacent blade sections 4 about the rotation axis of the cross-flow wind turbine is defined as the misalignment angle; Where -10°≤α≤10°.

[0038] like Figure 6 As shown, the rotation axis of the cross-flow wind turbine is defined as the line connecting the centers of multiple cover bodies 3, thus clarifying the rotation reference of the wind turbine. In each blade section 4, the serrated structure of adjacent blades is projected at the same position on the rotation axis, and the cuts 2 of multiple blades are arranged in a ring, ensuring the uniformity of the circumferential airflow division of the wind turbine, so that the airflow in each direction can be effectively affected by the cuts 2, avoiding local airflow turbulence. The circumferential included angle α (misalignment angle) of adjacent blade sections 4 around the rotation axis is limited to -10°≤α≤10°. By adjusting the misalignment angle, the airflow phase between adjacent blade sections 4 can be staggered, avoiding the superposition of vortex shedding frequencies of different blade sections 4 to form resonance noise, while making the wind turbine airflow more uniform and reducing airflow fluctuations.

[0039] To further explain, in each of the blade portions 4, the center of the cover 3 is defined as the center O, the center corresponding to the root edge 11 of the blade body 1 is defined as O1, and the center corresponding to the top edge 13 of the blade body 1 is defined as O2. Define ∠O1OO2, formed by centers O1, O, and O2, as the blade tilt angle β; Where β = γ × L, and γ ≤ 0.08° / mm, γ is the blade tilt coefficient.

[0040] like Figure 7-8 As shown, the center of the cover 3 is defined as the center O, the root edge 11 of the blade corresponds to the center O1, and the top edge 13 of the blade corresponds to the center O2. ∠O1OO2 is the blade tilt angle β, and β = γ × L (γ ≤ 0.08° / mm). The blade tilt angle directly affects the axial flow resistance of the airflow. The limitation of the tilt coefficient γ ensures that the blade tilt angle will not be too large. When γ exceeds 0.08° / mm, the blade tilt angle increases, which will significantly hinder the axial flow of the airflow, resulting in a decrease in air supply efficiency. The design of γ ≤ 0.08° / mm ensures that the blade has a certain tilt angle to adapt to the overall aerodynamic layout of the impeller, while controlling the axial flow resistance within a reasonable range, ensuring that the airflow can pass smoothly through the impeller.

[0041] To further verify the performance advantages of the present invention, simulation tests were conducted on cross-flow impellers including those with no trailing edge serrations, those with single-size trailing edge serrations, and those with trailing edge serrations on the blades of the present invention. The tests focused on five core performance indicators: rotational speed, noise, air volume, power, and peak power. The rotational speed covered the entire operating range from 870 r / min to 1590 r / min to ensure that the data could comprehensively reflect the performance under different operating conditions. The specific test results are shown in the table below.

[0042]

[0043] The above data analysis shows that across the entire speed range, the noise, airflow, and power of all three structures decrease as the speed decreases. In terms of noise control, the structure of this invention achieves an average noise reduction of 1.56% compared to the traditional serrated structure without a tail edge, and is on par with or slightly better than the single-size serrated structure. Furthermore, the peak noise is significantly optimized, with an average reduction of over 32% across the entire speed range, and a peak noise level of only 9 at 870 r / min, representing reductions of 40% and 35.7% compared to the traditional structure and the single-size structure, respectively.

[0044] In terms of airflow retention, the structure of this invention exhibits the slowest attenuation rate, achieving a retention rate of 98%, which is 3.73 percentage points higher than the single-size sawtooth structure. The airflow at 1590 r / min is 619.9 m³ / min. 3 / h, 22.9m taller than a single-size structure. 3 / h, effectively compensating for its air volume loss defect.

[0045] In terms of power consumption, the structure of this invention is similar to that of a single-size sawtooth structure, and slightly lower than that of a traditional sawtooth structure without a tail edge. At 1590 r / min, the power is 33.4 W, which is only 0.6 W lower than that of a traditional sawtooth structure without a tail edge. It achieves dual optimization of noise reduction and airflow maintenance at the cost of minimal power consumption, thus achieving a balance among the three.

[0046] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A cross-flow fan blade trailing edge serrated structure, characterized in that, Includes a blade body (1), the peripheral outline of which is formed by the blade root edge (11), the blade tail edge (12), the blade top edge (13) and the blade leading edge (14); The main body of the fan blade (1) has a pressure surface (15) and a suction surface (16). The pressure surface (15) and the suction surface (16) are arranged opposite to each other. The pressure surface (15) is recessed towards the suction surface (16) so that the suction surface (16) is convex. The cross-sectional shape of the pressure surface (15), the cross-sectional shape of the suction surface (16), the root edge (11) of the fan blade, and the top edge (13) of the fan blade are arranged in an arc. The blade trailing edge (12) has multiple incisions (2) recessed inward, and adjacent incisions (2) are not the same.

2. The cross-flow fan blade trailing edge serrated structure according to claim 1, characterized in that, A cutting plane is made through the top edge (13) of the blade to form the suction surface (16). Under the projection of the cutting plane, the root edge (11), the tail edge (12), the top edge (13), and the leading edge (14) of the blade sequentially form the root edge profile, the tail edge profile, the top edge profile, and the leading edge profile, and the cut (2) forms the cut profile. The root edge profile and the top edge profile of the blade are arranged in parallel, the trailing edge profile and the leading edge profile of the blade are arranged in parallel, and the shape of the cut profile includes at least one of triangle, rectangle or trapezoid.

3. The cross-flow fan blade trailing edge serrated structure according to claim 2, characterized in that, The vertical distance between the root edge profile of the wind turbine blade and the tip edge profile of the wind turbine blade is defined as the axial length L of the wind turbine blade. The arrangement order of the multiple cuts (2) is defined as starting from the root edge (11) of the blade and ending at the top edge (13) of the blade; The vertical distance between the center of the cut-out profile at the first end and the root edge profile of the blade is defined as l3; The vertical distance between the center of the cutout profile at the end and the top edge profile of the blade is defined as l1; Among them, l1≥3.5%L, l3≥11%L.

4. The cross-flow fan blade trailing edge serrated structure according to claim 3, characterized in that, The cut (2) mentioned above is defined as the first cut (21), and the cut (2) adjacent to the first cut (21) is defined as the second cut (22). The center-to-center distance between the first incision (21) and the second incision (22) is defined as l2; Among them, l2≥8%L.

5. The cross-flow fan blade trailing edge serrated structure according to claim 4, characterized in that, Define the depth of the first cut (21) as h1, and define the depth of the second cut (22) as h2; Where h2 = (0.75~1.25)h1, h1 ≤ 14%H.

6. The serrated trailing edge structure of a cross-flow fan blade according to claim 4, characterized in that, Define the opening angle of the first cut (21) as θ1, and define the opening angle of the second cut (22) as θ2; Where 0°≤θ1≤90°, 0°≤θ2≤90°.

7. The cross-flow fan blade trailing edge serrated structure according to claim 4, characterized in that, The bottom width of the first cut (21) is defined as a1, and the bottom width of the second cut (22) is defined as a2. Where 0≤a2≤a1≤6%L.

8. A cross-flow impeller, characterized in that, It includes multiple covers (3) and multiple blade portions (4), with one blade portion (4) disposed between two adjacent covers (3); The blade section (4) includes a plurality of blade bodies (1), which are arranged around the center of the cover (3). The blade trailing edge (12) of the blade body (1) is provided with a serrated structure as described in any one of claims 2-7. The root edge (11) of the blade body (1) is fixedly installed to the cover (3) through the small end mounting part (5), and the top edge (13) of the blade body (1) is fixedly installed to the cover (3) through the large end mounting part (6). Under the projection of the tangent plane, the vertical distance between the leading edge profile and the trailing edge profile of the wind turbine blade is defined as the radial length H of the wind turbine blade; The diameter of the cover (3) is defined as the diameter D of the impeller; Among them, 9%D≤H≤13%D.

9. A cross-flow impeller according to claim 8, characterized in that, Define the straight line connecting the centers of the multiple covers (3) as the rotation axis of the cross-flow fan; In each blade section (4), the serrated structures on two adjacent blade bodies (1) are projected at the same position on the rotation axis of the blade body (1), and the cuts (2) on multiple blade bodies (1) are arranged in a ring. Define the circumferential angle α between adjacent blade sections (4) around the rotation axis of the cross-flow wind turbine as the misalignment angle; Where -10°≤α≤10°.

10. A cross-flow wind turbine according to claim 8, characterized in that, In each of the blade portions (4), the center of the cover (3) is defined as the center O, the center of the root edge (11) of the blade body (1) is defined as O1, and the center of the top edge (13) of the blade body (1) is defined as O2. Define ∠O1OO2, formed by centers O1, O, and O2, as the blade tilt angle β; Where β = γ × L, and γ ≤ 0.08° / mm, γ is the blade tilt coefficient.

Images