A large wind volume and high energy efficiency ratio livestock wind blade and a wind wheel applying the same

Abstract

The present application relates to the technical field of ventilation equipment for livestock, and particularly relates to a large-air-volume high-energy-efficiency livestock fan blade and a fan wheel using the same, wherein the livestock fan blade aims at the problems of insufficient air volume and low energy efficiency of the existing livestock axial flow fan under high back pressure conditions, and optimizes the chord length difference between the blade root edge and the blade top edge and the overall area distribution of the blade, combines the gradient sweep design of the blade front edge, the blade main body center line and the blade tail edge, and designs the double concave parts of the blade tail edge by limiting the length of the concave area and the differential concave degree, so that the blade body can effectively capture and push more air under high back pressure conditions, and realize large air volume output and high energy efficiency under high pressure conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ventilation equipment for livestock, and in particular to a large-wind-volume high-energy-efficiency ratio livestock fan blade and a fan wheel using the same. BACKGROUND

[0002] In the livestock breeding environment, the ventilation equipment is one of the key equipment for maintaining the stability of the breeding environment, which needs to operate under high back pressure (high pressure) working condition to ensure the air circulation, reduce the humidity and harmful gas concentration in the breeding house. The existing livestock axial flow fan often has the problems of insufficient wind volume and low energy efficiency ratio under high back pressure working condition, mainly because the blade structure design is unreasonable, the blade area and sweep degree are not optimized, and the tail edge airflow guiding effect is poor, resulting in large power loss, and the demand for large wind volume and high energy efficiency ratio cannot be met. Therefore, there is an urgent need for a livestock fan wheel structure that can realize large wind volume and high energy efficiency ratio under high pressure working condition. SUMMARY

[0003] One purpose of the present application is to provide a large-wind-volume high-energy-efficiency ratio livestock fan blade, which aims to solve the problems of insufficient wind volume and low energy efficiency ratio of the existing livestock axial flow fan under high back pressure working condition by optimizing the blade structure parameters and tail edge design to realize large wind volume output and high energy efficiency ratio under high pressure working condition.

[0004] Another purpose of the present application is to provide a fan wheel using the above-mentioned large-wind-volume high-energy-efficiency ratio livestock fan blade.

[0005] To achieve this purpose, the present application adopts the following technical solutions:

[0006] A large-wind-volume high-energy-efficiency ratio livestock fan blade, comprising a blade body;

[0007] The blade body is in a sheet structure, and the periphery contour of the blade body is formed by a blade root edge, a blade leading edge, a blade top edge and a blade tail edge;

[0008] The connecting points between the blade root edge, the blade leading edge, the blade top edge and the blade tail edge are defined as design point B3, design point B1, design point A1 and design point A3 in sequence, and form curves B3B1, B1A1, A1A3 and A3B3 in sequence;

[0009] The midpoint on the curve B3B1 is defined as design point B2, and the midpoint on the curve A1A3 is defined as design point A2, and the curve B2A2 is formed by connecting the design point B2 and the design point A2;

[0010] The degree of sweep of the blade body is jointly controlled by the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3, and the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3 are set in descending order.

[0011] Curves B1B3 and A1A3 are concentric circular arcs with the same center O. The area of ​​the blade body is jointly controlled by curves B3B1, B1A1, A1A3, and A3B3, and the chord length L of curve B3B1 is... B The chord length L is smaller than that of the curve A1A3. A ;

[0012] Two points on the curve A3B3 are defined as design point E and design point K. Design point E is located close to or overlaps with design point A3, and design point K is located close to design point B3. The edge between design point E and design point K is defined as a concave edge, and the length of the concave edge is less than one-third of the length of the leaf trailing edge. The concave edge has two concave portions, and the degree of concavity of the two concave portions decreases from design point E to design point K.

[0013] Preferably, the design point A1, the center O, and the design point B1 are connected in sequence to form an included angle ∠A1OB1, and the design point A3, the center O, and the design point B3 are connected in sequence to form an included angle ∠A3OB3;

[0014] Among them, 77mm < L B <83mm, 173mm <L A <179mm, 18°<∠A1OB1<25°, 45°<∠A3OB3<50°.

[0015] Preferably, the straight line connecting the design point B1 and the design point A1 is defined as the straight line B1A1, and a parallel line D1C1 parallel to the straight line B1A1 is drawn. The straight line distance between the straight line B1A1 and the parallel line D1C1 is defined as the curvature h1 of the curve B1A1.

[0016] Define the two endpoints of the parallel line D1C1 as design point D1 and design point C1, respectively. Connect the design points A1, B1 and D1 in sequence to form an angle ∠A1B1D1, and connect the design points C1, A1 and B1 in sequence to form an angle ∠C1A1B1.

[0017] Among them, 50mm < h1 < 55mm, 40° < ∠A1B1D1 < 45°, and 32° < ∠C1A1B1 < 37°.

[0018] Preferably, the straight line connecting the design point B2 and the design point A2 is defined as the straight line B2A2, and a parallel line D2C2 is drawn parallel to the straight line B2A2. The straight line distance between the straight line B2A2 and the parallel line D2C2 is defined as the curvature h2 of the curve B2A2.

[0019] Define the two endpoints of the parallel line D2C2 as design point D2 and design point C2 respectively. Connect the design points A2, B2 and D2 in sequence to form an included angle ∠A2B2D2. Connect the design points C2, A2 and B2 in sequence to form an included angle ∠C2A2B2.

[0020] Among them, 40mm < h2 < 45mm, 33° < ∠A2B2D2 < 38°, and 27° < ∠C2A2B2 < 32°.

[0021] Preferably, the straight line connecting the design point B3 and the design point A3 is defined as the straight line B3A3, and a parallel line D3C3 is drawn parallel to the straight line B3A3. The straight line distance between the straight line B3A3 and the parallel line D3C3 is defined as the curvature h3 of the curve B3A3.

[0022] Define the two endpoints of the parallel line D3C3 as design point D3 and design point C3 respectively. Connect the design points A3, B3 and D3 in sequence to form an included angle ∠A3B3D3. Connect the design points C3, A3 and B3 in sequence to form an included angle ∠C3A3B3.

[0023] Among them, 32mm < h3 < 37mm, 25° < ∠A3B3D3 < 30°, and 22° < ∠C3A3B3 < 27°.

[0024] Preferably, the curvatures h1, h2, and h3 form a sequence of curvature tolerances Δh that are unequal and decreasing.

[0025] Among them, 6mm < Δh < 10mm.

[0026] Preferably, the included angles ∠A1B1D1, ∠A2B2D2, and ∠A3B3D3 form a sequence of leaf root common differences ΔB that are unequal and decreasing.

[0027] Among them, 5° < ΔB < 10°.

[0028] Preferably, the included angles ∠C1A1B1, ∠C2A2B2, and ∠C3A3B3 form a sequence of leaf tip tolerances ΔA that are unequal and decreasing.

[0029] Among them, 3° < ΔA < 7°.

[0030] Preferably, a point is randomly selected on the edge of the recessed arrangement as the design point H;

[0031] Connect the design point E and the design point H to form curve EH;

[0032] Connect the design point H and the design point K to form curve HK;

[0033] The curves EH and HK form the two recesses;

[0034] The curve EH is formed by a B-spline curve and is controlled by design points F and G. The design points F, E, and H are connected in sequence to form an angle ∠FEH, the design points E, F, and G are connected in sequence to form an angle ∠EFG, the design points F, G, and H are connected in sequence to form an angle ∠FGH, and the design points G, H, and E are connected in sequence to form an angle ∠GHE. The straight line connecting design points E and H is defined as the straight line EH.

[0035] The curve HK is formed by a B-spline curve. The curve HK is controlled by design point I and design point J. The design points I, H and K are connected in sequence to form an angle ∠IHK. The design points H, I and J are connected in sequence to form an angle ∠HIJ. The design points I, J and K are connected in sequence to form an angle ∠IJK. The design points J, K and H are connected in sequence to form an angle ∠JKH. The straight line connecting design point H and design point K is defined as the straight line HK.

[0036] Among them, 40° < ∠FEH < 45°, 110° < ∠EFG < 115°, 153° < ∠FGH < 158°, 2° < ∠GHE < 6°, and 28mm < the length of line EH < 32mm;

[0037] 52° < ∠IHK < 58°, 62° < ∠HIJ < 68°, 125° < ∠IJK < 130°, 5° < ∠JKH < 10°, 44mm < length of line HK < 48mm.

[0038] A wind turbine includes a hub and several high-volume, high-efficiency livestock wind blades as described above, wherein the several high-volume, high-efficiency livestock wind blades are evenly distributed along the axial direction of the hub.

[0039] In a certain type of livestock wind blade with large air volume and high energy efficiency, the center O is arranged to coincide with the rotation axis O' of the hub.

[0040] The recessed arrangement is located at 75%-100% of the blade height of the wind turbine.

[0041] One of the above technical solutions has the following beneficial effects:

[0042] 1. High air volume output under high pressure conditions: By optimizing the difference in chord length between the blade root edge and the blade tip edge and the overall area distribution of the blade, combined with the gradient sweep design of the blade leading edge, the center line of the blade body and the blade trailing edge, the blade body can effectively capture and push more air under high back pressure conditions, meeting the needs of livestock farming environment for high air volume ventilation.

[0043] 2. High energy efficiency ratio operation: The double concave part of the blade trailing edge is designed to precisely reduce eddy current losses in the high-work area by limiting the length of the concave area and differentiating the degree of concavity, while avoiding resistance redundancy in the low-work area. Under the premise of ensuring air volume output, the power consumption of the impeller is significantly reduced, the energy efficiency ratio of the equipment is improved, and the long-term energy consumption cost of livestock farming is reduced.

[0044] 3. Strong structural adaptability: The overall structure is optimized through the coordinated design of contour curves, sweep degree and local concavity to ensure smooth airflow and reasonable pressure distribution when the livestock fan blades rotate, adapting to the complex operating conditions of high back pressure in the livestock breeding environment, and has stable and reliable ventilation performance. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a livestock wind turbine blade structure with large air volume and high energy efficiency.

[0046] Figure 2 This is a schematic diagram of the overall design of the blade body in a livestock wind turbine with a large air volume and high energy efficiency ratio.

[0047] Figure 3 This is a detailed design schematic diagram of design points B3, B2, B1, A1, A2, and A3 in a livestock wind turbine blade with large air volume and high energy efficiency ratio.

[0048] Figure 4 This is a schematic diagram of the overall design of the recessed part in a livestock fan blade with a large air volume and high energy efficiency ratio.

[0049] Figure 5 This is a detailed design schematic diagram of design points E, F, G, H, I, J, and K in a livestock wind turbine blade with a large air volume and high energy efficiency ratio.

[0050] Figure 6 This is an axial projection diagram of a wind turbine of livestock wind turbine blades with large air volume and high energy efficiency ratio according to the present invention.

[0051] Figure 7 This is a performance test diagram of a livestock wind turbine blade with a large air volume and high energy efficiency ratio according to the present invention.

[0052] In the attached diagram: leaf root edge 1, leaf front edge 2, leaf apex edge 3, leaf tail edge 4, and depression 5. Detailed Implementation

[0053] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] A high-volume, high-energy-efficiency livestock wind turbine blade, comprising the blade body;

[0058] The leaf body has a sheet-like structure, and the peripheral outline of the leaf body is formed by the leaf root edge 1, the leaf leading edge 2, the leaf apex edge 3, and the leaf trailing edge 4.

[0059] The connection points between the leaf root edge 1, leaf leading edge 2, leaf apex edge 3 and leaf trailing edge 4 are defined as design point B3, design point B1, design point A1 and design point A3, respectively, and curves B3B1, B1A1, A1A3 and A3B3 are formed in sequence.

[0060] Define the midpoint of the curve B3B1 as the design point B2, define the midpoint of the curve A1A3 as the design point A2, and connect the design point B2 and the design point A2 to form the curve B2A2.

[0061] The degree of sweep of the blade body is jointly controlled by the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3, and the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3 are set in descending order.

[0062] Curves B1B3 and A1A3 are concentric circular arcs with the same center O. The area of ​​the blade body is jointly controlled by curves B3B1, B1A1, A1A3, and A3B3, and the chord length L of curve B3B1 is... B The chord length L is smaller than that of the curve A1A3. A ;

[0063] Two points on the curve A3B3 are defined as design point E and design point K, respectively. Design point E is set close to or overlaps with design point A3, and design point K is set close to design point B3. The edge between design point E and design point K is defined as a concave edge, and the length of the concave edge is less than one-third of the length of the leaf tail edge 4. The concave edge has two concave portions 5, and the degree of concavity of the two concave portions 5 decreases from design point E to design point K.

[0064] like Figures 1-5 As shown, this high-volume, high-efficiency livestock fan blade achieves high air volume output and high energy efficiency under high back pressure conditions through precise design of the blade's main body contour structure, sweep degree, and trailing edge concavity features. The specific working principle is as follows:

[0065] Firstly, the blade area and airflow contact are optimized: the peripheral contour of the blade body is formed by the root edge 1, the leading edge 2, the apex edge 3, and the trailing edge 4. Among them, the root edge correlation curve B3B1 and the apex edge correlation curve A1A3 are concentric arcs, and the chord length L of curve B3B1 is... B That is, the leaf root chord length is less than the chord length L of curve A1A3. A This refers to the chord length at the blade tip. This design optimizes the overall area distribution of a single livestock fan blade through differentiated chord length control, enabling the blade to make effective contact with more air during rotation, thus providing a foundation for high-volume air output.

[0066] Secondly, the sweep angle plays a crucial role in airflow guidance: the sweep angle of the blade body is jointly controlled by the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3, with h1>h2>h3 in a decreasing order, forming a gradient airflow guidance structure. This gradient sweep design guides the airflow smoothly along the blade surface, reducing airflow separation and turbulence losses, and maintaining stable airflow propulsion capability even under high back pressure conditions, ensuring airflow output.

[0067] Finally, energy efficiency optimization is achieved through the double-concave trailing edge: the length of the concave arrangement edge (section E to K) of the blade trailing edge (curve A3B3) is less than one-third of the total length of the trailing edge, and two concave sections 4 are set inward. The degree of concavity decreases from the design point E (near the blade tip edge) to the design point K (near the blade root edge). Based on the structural characteristics, the concave area concentrates its effect on the local area with strong work capacity of the blade body, namely the high-wind-speed section near the blade tip edge, where the linear velocity is high and airflow energy is concentrated. The double concave sections manage the high-speed airflow, reducing energy loss caused by trailing edge vortices; simultaneously, limiting the length of the concave area and reducing the degree of concavity on the blade root side avoids increasing ineffective drag in areas with weaker work capacity. By precisely reducing unnecessary energy loss, the rotor operating power is reduced with minimal airflow loss, thereby improving the energy efficiency ratio.

[0068] To further explain, the design point A1, the center O, and the design point B1 are connected in sequence to form an angle ∠A1OB1, and the design point A3, the center O, and the design point B3 are connected in sequence to form an angle ∠A3OB3;

[0069] Among them, 77mm < L B <83mm, 173mm <L A <179mm, 18°<∠A1OB1<25°, 45°<∠A3OB3<50°.

[0070] like Figure 2 As shown, by differentiating the chord length between the blade root edge 1 and the blade tip edge 3, the blade area gradually increases from the blade root edge to the blade tip edge within a certain range, expanding the effective contact range between the livestock fan blade and the air, and providing a basic area guarantee for large air volume output. At the same time, by controlling the angle parameters, the spatial distribution of the livestock fan blade in the plane of rotation is optimized: ∠A1OB1, the leading edge angle of the livestock fan blade, ensures that the airflow can be efficiently introduced into the blade pressure surface, while ∠A3OB3, the trailing edge angle of the livestock fan blade, provides a reasonable channel for airflow discharge. The angle difference between the two allows the livestock fan blade to form a continuous and stable airflow propulsion path when rotating, maintaining a strong air pushing capacity even under high back pressure conditions.

[0071] To further explain, the straight line connecting the design point B1 and the design point A1 is defined as the straight line B1A1. A parallel line D1C1 is drawn parallel to the straight line B1A1. The straight line distance between the straight line B1A1 and the parallel line D1C1 is defined as the curvature h1 of the curve B1A1.

[0072] Define the two endpoints of the parallel line D1C1 as design point D1 and design point C1, respectively. Connect the design points A1, B1 and D1 in sequence to form an angle ∠A1B1D1, and connect the design points C1, A1 and B1 in sequence to form an angle ∠C1A1B1.

[0073] Among them, 50mm < h1 < 55mm, 40° < ∠A1B1D1 < 45°, and 32° < ∠C1A1B1 < 37°.

[0074] like Figure 3 As shown, the curvature h1 of curve B1A1 is limited to 50mm < h1 < 55mm, and this parameter determines the curvature amplitude of the leading edge. By setting a reasonable curvature, a smooth arc transition is formed at the leading edge of the blade. When the airflow contacts the blade, it can be gently guided into the livestock fan blade along the curved surface, reducing energy loss caused by airflow impact. At the same time, the angle parameters 40° < ∠A1B1D1 < 45° and 32° < ∠C1A1B1 < 37° form a gradient angle distribution, which adapts to the linear velocity difference of the livestock fan blade from the leading point of the blade root edge to the leading point of the blade tip edge. This ensures that the airflow at different radial positions can stably adhere to the surface of the livestock fan blade, avoiding vortex losses caused by airflow separation and providing a smooth airflow path for large air volume output.

[0075] To further explain, the straight line connecting the design point B2 and the design point A2 is defined as the straight line B2A2. A parallel line D2C2 is drawn parallel to the straight line B2A2. The straight line distance between the straight line B2A2 and the parallel line D2C2 is defined as the curvature h2 of the curve B2A2.

[0076] Define the two endpoints of the parallel line D2C2 as design point D2 and design point C2 respectively. Connect the design points A2, B2 and D2 in sequence to form an included angle ∠A2B2D2. Connect the design points C2, A2 and B2 in sequence to form an included angle ∠C2A2B2.

[0077] Among them, 40mm < h2 < 45mm, 33° < ∠A2B2D2 < 38°, and 27° < ∠C2A2B2 < 32°.

[0078] like Figure 3As shown, the curvature h2 of curve B2A2 is limited to 40mm < h2 < 45mm, which determines the curvature amplitude in the middle of the livestock fan blade. By setting a reasonable curvature, an arc-shaped structure adapted to airflow is formed in the middle of the livestock fan blade. When the airflow enters from the leading edge of the blade, it can smoothly transition along the middle curve B2A2, reducing turbulence and separation phenomena in the middle section of the livestock fan blade. At the same time, the angle parameters 33° < ∠A2B2D2 < 38° and 27° < C2A2B2 < 32° form a gradient distribution, adapting to the linear velocity difference from the midpoint of the root edge to the midpoint of the tip edge of the livestock fan blade. This ensures stable airflow at different radial positions in the middle of the livestock fan blade, avoids energy loss caused by sudden changes in local pressure, and provides structural support for a smooth transition of airflow from the leading edge to the trailing edge of the blade.

[0079] To further explain, the straight line connecting design point B3 and design point A3 is defined as straight line B3A3. A parallel line D3C3 is drawn parallel to straight line B3A3. The straight line distance between straight line B3A3 and parallel line D3C3 is defined as the curvature h3 of curve B3A3.

[0080] Define the two endpoints of the parallel line D3C3 as design point D3 and design point C3 respectively. Connect the design points A3, B3 and D3 in sequence to form an included angle ∠A3B3D3. Connect the design points C3, A3 and B3 in sequence to form an included angle ∠C3A3B3.

[0081] Among them, 32mm < h3 < 37mm, 25° < ∠A3B3D3 < 30°, and 22° < ∠C3A3B3 < 27°.

[0082] like Figure 3 As shown, the curvature h3 of curve B3A3 is limited to 32mm < h3 < 37mm, and this parameter determines the curvature amplitude of the blade trailing edge. By setting a reasonable curvature, a smooth arc transition structure is formed at the blade trailing edge. When the airflow passes through the pressure surface of the blade to the trailing edge, it can be gently discharged along the curved surface, reducing the wake vortex generated when the airflow leaves the blade. At the same time, the angle parameters 25° < ∠A3B3D3 < 30° and 22° < ∠C3A3B3 < 27° form a gradient distribution, which is adapted to the linear velocity reduction characteristics of the livestock wind turbine blade from the trailing point of the blade root edge to the trailing point of the blade tip edge. This ensures that the airflow at different radial positions can be stably separated at the blade trailing edge, avoiding local turbulence loss caused by the airflow impacting the blade trailing edge, and providing structural guidance for the efficient discharge of airflow.

[0083] To further explain, the curvature h1, curvature h2, and curvature h3 form a series of curvature tolerances Δh that are unequal and decreasing.

[0084] Among them, 6mm < Δh < 10mm.

[0085] The above design ensures a smooth, gradient transition in the curvature of the livestock wind turbine blades from the leading edge to the trailing edge, adapting to the dynamic changes in airflow from intake to exhaust: the leading edge requires a larger curvature (h1) to efficiently capture airflow, the centerline curvature (h2) is slightly smaller to guide smooth airflow, and the trailing edge curvature (h3) is minimal to reduce vortex losses during exhaust. This decreasing tolerance ensures a continuous, abrupt change in curvature, preventing airflow separation or turbulence on the blade surface due to structural abrupt changes, thereby reducing energy loss.

[0086] To further explain, the included angles ∠A1B1D1, ∠A2B2D2, and ∠A3B3D3 form a sequence of leaf root common differences ΔB that are unequal and decreasing.

[0087] Among them, 5° < ΔB < 10°.

[0088] The above design results in a lower linear velocity and weaker airflow energy in the blade root region of the livestock fan blades. The gradient angle design is adapted to this characteristic: the leading edge blade root angle (∠A1B1D1) is larger to guide the low-speed airflow smoothly into the fan; the midline blade root angle (∠A2B2D2) is slightly smaller to maintain airflow stability; and the trailing edge blade root angle (∠A3B3D3) is the smallest to reduce resistance when the low-speed airflow exits. This decreasing tolerance ensures a smooth change in the blade root angle, avoiding the formation of vortices in the blade root region due to abrupt angle changes, thus reducing ineffective energy consumption.

[0089] To further explain, the included angles ∠C1A1B1, ∠C2A2B2, and ∠C3A3B3 form a sequence of unequal and decreasing leaf tip tolerances ΔA;

[0090] Among them, 3° < ΔA < 7°.

[0091] The above design results in high linear velocity and concentrated airflow energy in the blade tip region of the livestock fan blade. The gradient angle design is adapted to this characteristic: the leading edge blade tip angle (∠C1A1B1) is relatively large to efficiently capture high-speed airflow; the midline blade tip angle (∠C2A2B2) is slightly smaller to guide the high-speed airflow smoothly; and the trailing edge blade tip angle (∠C3A3B3) is the smallest to reduce kinetic energy loss when the high-speed airflow is exhausted. The decreasing tolerance ensures continuous change in blade tip angle, avoiding separation of high-speed airflow due to abrupt angle changes, and maximizing the utilization of airflow kinetic energy.

[0092] To further explain, any point on the edge of the recessed arrangement is selected as the design point H;

[0093] Connect the design point E and the design point H to form curve EH;

[0094] Connect the design point H and the design point K to form curve HK;

[0095] The curves EH and HK form the two recesses;

[0096] The curve EH is formed by a B-spline curve and is controlled by design points F and G. The design points F, E, and H are connected in sequence to form an angle ∠FEH, the design points E, F, and G are connected in sequence to form an angle ∠EFG, the design points F, G, and H are connected in sequence to form an angle ∠FGH, and the design points G, H, and E are connected in sequence to form an angle ∠GHE. The straight line connecting design points E and H is defined as the straight line EH.

[0097] The curve HK is formed by a B-spline curve. The curve HK is controlled by design point I and design point J. The design points I, H and K are connected in sequence to form an angle ∠IHK. The design points H, I and J are connected in sequence to form an angle ∠HIJ. The design points I, J and K are connected in sequence to form an angle ∠IJK. The design points J, K and H are connected in sequence to form an angle ∠JKH. The straight line connecting design point H and design point K is defined as the straight line HK.

[0098] Among them, 40° < ∠FEH < 45°, 110° < ∠EFG < 115°, 153° < ∠FGH < 158°, 2° < ∠GHE < 6°, and 28mm < the length of line EH < 32mm;

[0099] 52° < ∠IHK < 58°, 62° < ∠HIJ < 68°, 125° < ∠IJK < 130°, 5° < ∠JKH < 10°, 44mm < length of line HK < 48mm.

[0100] like Figures 4-5 As shown, by optimizing the angle and length parameters of curves EH and HK, the double concave section precisely matches the linear velocity distribution of the blade from the tip to the root (higher at the tip and lower at the root): the gentle concave design of curve EH on the tip side, which is located at high wind speed, sorts out the airflow and reduces eddies; the gentle concave design of curve HK on the root side, which is located at medium and low wind speed, balances drag and thrust. The two work together to minimize the energy loss of the trailing edge airflow from introduction to exhaust.

[0101] It should be noted that the relationships between the above design points are all calculated under the axial projection of the main pressure surface of the blade in the livestock wind turbine blade.

[0102] A wind turbine includes a hub 20 and several high-volume, high-efficiency livestock wind blades 10 as described above, wherein the several high-volume, high-efficiency livestock wind blades 10 are evenly distributed along the axial direction of the hub 20.

[0103] In a certain type of livestock wind blade 10 with large air volume and high energy efficiency, the center O is arranged to coincide with the rotation axis O' of the hub 20.

[0104] The recessed arrangement is located at 75%-100% of the blade height of the wind turbine.

[0105] It should be noted that blade height refers to the linear distribution between the rotation axis O' of the wind turbine and the tip edge of the blade under axial projection.

[0106] The aforementioned recessed arrangement is located at 75%-100% of the blade height of the wind turbine, meaning that the straight-line distances KO' and EO' from the design point K and design point E of the wind turbine blade to the rotation axis O' of the wind turbine are both distributed within the 75%-100% blade height range. Figure 6 As shown.

[0107] Since the linear velocity of the wind turbine increases with the blade height, the 75%-100% blade height region is the region with the highest linear velocity when the wind turbine rotates. The airflow energy is concentrated in this region, and placing the double concave section here can accurately guide the high-speed airflow: by sorting out the airflow direction through the concave structure, the trailing edge vortex loss is reduced, and more kinetic energy is converted into the effective work of pushing air.

[0108] In areas where the blade height is below 75%, the linear velocity is low and the airflow energy is weak. If a concave structure were installed in this area, it would not only fail to effectively guide the high-speed airflow but would also increase airflow resistance due to the concave shape, leading to reduced airflow and power loss. Therefore, the concave area is limited to the upper section of the high blade to avoid the accumulation of ineffective resistance.

[0109] To further illustrate the improved performance of the livestock wind turbine blade using a high-volume, high-efficiency blade, tests were conducted on the air volume, power, and energy efficiency ratio (air volume / power) under different static pressure conditions, with constant rotational speed. The results are as follows:

[0110]

[0111] Combining the above table with Figure 7 It can be seen that as the static pressure increases from 0 Pa to 200 Pa, the wind turbine's air volume shows a continuous decreasing trend. Specifically, the air volume is highest at 0 Pa, reaching 7685 m³ / h; when the static pressure rises to 200 Pa, the air volume drops to 3084 m³ / h. Overall, the air volume decreases gradually with the increase of static pressure, which is consistent with the natural attenuation of air volume under high back pressure conditions.

[0112] Contrary to the trend of air volume change, the power continuously increases with the increase of static pressure. The power is the lowest at 0 Pa, at 303 W; when the static pressure rises to 200 Pa, the power increases to 500 W, reflecting that the wind turbine needs to consume more energy to overcome system resistance under high static pressure conditions.

[0113] It is worth noting that the energy efficiency ratio (the ratio of air volume to power) generally decreases as static pressure increases, but the rate of decrease varies significantly across different static pressure ranges:

[0114] In the static pressure range of 0Pa-120Pa, the energy efficiency ratio drops from 25.4 to 12.2, a significant decrease, with an average decrease of about 3.3 for every 30Pa increase in pressure.

[0115] In the static pressure range of 120Pa-200Pa, the energy efficiency ratio decreased from 12.2 to 6.2, with the rate of decrease slowing down significantly. On average, the energy efficiency ratio decreased by about 1.0 for every 20Pa increase, which was significantly lower than that in the low static pressure range.

[0116] Therefore, this type of wind turbine with a large air volume and high energy efficiency ratio exhibits excellent performance adaptability under high static pressure conditions:

[0117] In the high back pressure operating environment (high static pressure condition) commonly seen in livestock farming, although the air volume still decreases as the static pressure increases, the rate of air volume decrease is more gradual under high static pressure (120Pa-200Pa) conditions compared to the low static pressure range, and the power increase is effectively controlled. This characteristic allows the wind turbine to maintain a relatively high energy efficiency ratio while ensuring minimal air volume loss when operating at high static pressure, significantly outperforming the energy efficiency degradation performance in the low static pressure range.

[0118] In summary, the structural design of this invention, such as the optimized blade sweep angle, double concave trailing edge, and precise parameter matching, effectively meets the core operational requirements of high back pressure in livestock farming. In practical application scenarios, it can achieve a balance between large air volume and high energy efficiency ratio, and has strong practical value.

[0119] 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 livestock fan blade with high air volume and high energy efficiency, characterized in that, Including the blade body; The leaf body has a sheet-like structure, and the peripheral outline of the leaf body is formed by the leaf root edge (1), the leaf leading edge (2), the leaf apex edge (3) and the leaf trailing edge (4); The connection points between the leaf root edge (1), leaf leading edge (2), leaf apex edge (3) and leaf trailing edge (4) are defined as design point B3, design point B1, design point A1 and design point A3, respectively, and curves B3B1, B1A1, A1A3 and A3B3 are formed in sequence. Define the midpoint of the curve B3B1 as the design point B2, define the midpoint of the curve A1A3 as the design point A2, and connect the design point B2 and the design point A2 to form the curve B2A2. The degree of sweep of the blade body is jointly controlled by the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3, and the curvature h1 of curve B1A1, the curvature h2 of curve B2A2, and the curvature h3 of curve A3B3 are set in descending order. Curves B1B3 and A1A3 are concentric circular arcs with the same center O. The area of ​​the blade body is jointly controlled by curves B3B1, B1A1, A1A3, and A3B3, and the chord length L of curve B3B1 is... B The chord length L is smaller than that of the curve A1A3. A ; Two points on the curve A3B3 are defined as design point E and design point K, respectively. Design point E is set close to or overlaps with design point A3, and design point K is set close to design point B3. The edge between design point E and design point K is defined as a concave edge, and the length of the concave edge is less than one-third of the length of the leaf tail edge (4). The concave edge has two concave parts (5) inwardly arranged, and the degree of concavity of the two concave parts (5) decreases from design point E to design point K. Connect the design point A1, the center O, and the design point B1 in sequence to form an included angle ∠A1OB1, and connect the design point A3, the center O, and the design point B3 in sequence to form an included angle ∠A3OB3; Among them, 77mm < L B <83mm, 173mm <L A <179mm, 18°<∠A1OB1<25°, 45°<∠A3OB3<50°; Define the straight line connecting the design point B1 and the design point A1 as the straight line B1A1, and draw a parallel line D1C1 parallel to the straight line B1A1. Define the straight line distance between the straight line B1A1 and the parallel line D1C1 as the curvature h1 of the curve B1A1. Define the two endpoints of the parallel line D1C1 as design point D1 and design point C1, respectively. Connect the design points A1, B1 and D1 in sequence to form an angle ∠A1B1D1, and connect the design points C1, A1 and B1 in sequence to form an angle ∠C1A1B1. Among them, 50mm < h1 < 55mm, 40° < ∠A1B1D1 < 45°, and 32° < ∠C1A1B1 < 37°.

2. The livestock wind turbine blade with large air volume and high energy efficiency ratio according to claim 1, characterized in that, Define the straight line connecting the design point B2 and the design point A2 as the straight line B2A2, and draw a parallel line D2C2 parallel to the straight line B2A2. Define the straight line distance between the straight line B2A2 and the parallel line D2C2 as the curvature h2 of the curve B2A2. Define the two endpoints of the parallel line D2C2 as design point D2 and design point C2 respectively. Connect the design points A2, B2 and D2 in sequence to form an included angle ∠A2B2D2. Connect the design points C2, A2 and B2 in sequence to form an included angle ∠C2A2B2. Among them, 40mm < h2 < 45mm, 33° < ∠A2B2D2 < 38°, and 27° < ∠C2A2B2 < 32°.

3. The livestock wind turbine blade with large air volume and high energy efficiency ratio according to claim 2, characterized in that, Define the straight line connecting design point B3 and design point A3 as straight line B3A3, draw a parallel line D3C3 parallel to straight line B3A3, and define the straight line distance between straight line B3A3 and parallel line D3C3 as the curvature h3 of curve B3A3. Define the two endpoints of the parallel line D3C3 as design point D3 and design point C3 respectively. Connect the design points A3, B3 and D3 in sequence to form an included angle ∠A3B3D3. Connect the design points C3, A3 and B3 in sequence to form an included angle ∠C3A3B3. Among them, 32mm < h3 < 37mm, 25° < ∠A3B3D3 < 30°, and 22° < ∠C3A3B3 < 27°.

4. The livestock wind turbine blade with large air volume and high energy efficiency ratio according to claim 3, characterized in that, The curvatures h1, h2, and h3 form a series of curvature tolerances Δh that are unequal and decreasing. Among them, 6mm < Δh < 10mm.

5. A livestock wind turbine blade with high air volume and high energy efficiency ratio according to claim 3, characterized in that, The included angles ∠A1B1D1, ∠A2B2D2, and ∠A3B3D3 form a sequence with unequal and decreasing leaf root common differences ΔB; Among them, 5° < ΔB < 10°.

6. The livestock wind turbine blade with large air volume and high energy efficiency ratio according to claim 3, characterized in that, The included angles ∠C1A1B1, ∠C2A2B2, and ∠C3A3B3 form a sequence of unequal and decreasing leaf tip tolerances ΔA; Among them, 3° < ΔA < 7°.

7. A livestock wind turbine blade with high air volume and high energy efficiency ratio according to claim 3, characterized in that, Take any point on the edge of the recessed arrangement as the design point H; Connect the design point E and the design point H to form curve EH; Connect the design point H and the design point K to form curve HK; The curves EH and HK form the two recesses; The curve EH is formed by a B-spline curve and is controlled by design points F and G. The design points F, E, and H are connected in sequence to form an angle ∠FEH, the design points E, F, and G are connected in sequence to form an angle ∠EFG, the design points F, G, and H are connected in sequence to form an angle ∠FGH, and the design points G, H, and E are connected in sequence to form an angle ∠GHE. The straight line connecting design points E and H is defined as the straight line EH. The curve HK is formed by a B-spline curve. The curve HK is controlled by design point I and design point J. The design points I, H and K are connected in sequence to form an angle ∠IHK. The design points H, I and J are connected in sequence to form an angle ∠HIJ. The design points I, J and K are connected in sequence to form an angle ∠IJK. The design points J, K and H are connected in sequence to form an angle ∠JKH. The straight line connecting design point H and design point K is defined as the straight line HK. Among them, 40° < ∠FEH < 45°, 110° < ∠EFG < 115°, 153° < ∠FGH < 158°, 2° < ∠GHE < 6°, and 28mm < the length of line EH < 32mm; 52° < ∠IHK < 58°, 62° < ∠HIJ < 68°, 125° < ∠IJK < 130°, 5° < ∠JKH < 10°, 44mm < length of line HK < 48mm.

8. A wind turbine, characterized in that, Includes a hub (20) and a plurality of high-volume, high-efficiency livestock wind turbine blades (10) as described in any one of claims 1-7, wherein the plurality of high-volume, high-efficiency livestock wind turbine blades (10) are uniformly distributed along the axial direction of the hub (20). In a certain type of livestock wind blade (10) with large air volume and high energy efficiency, the center O is arranged to coincide with the rotation axis O' of the hub (20); The recessed arrangement is located at 75%-100% of the blade height of the wind turbine.

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