Axial flow fan and top air outlet type air conditioner outdoor unit

Abstract

The application discloses an axial flow fan, and relates to the technical field of fans; the axial flow fan comprises a hub and blades; the blades are connected to the hub and arranged along the outer periphery of the hub; the blade comprises a leading edge and a trailing edge; the leading edge is located at the front end in the rotating direction of the blade; the trailing edge is located at the rear end in the rotating direction of the blade; a rectangular coordinate system is established on the axial flow fan; the projection of the blade on the plane xOy is a curve comprising a first curve and a second curve; the first curve is arranged corresponding to the leading edge of the blade; the second curve is arranged corresponding to the trailing edge of the blade; a line OA is formed between a point A on the first curve and the origin O; a first included angle alpha 1 is formed between the line OA and the y-axis; a line OB is formed between a point B on the second curve and the origin O; a second included angle alpha 2 is formed between the line OB and the y-axis; by limiting the relationship between the first included angle alpha 1 and the length of the line OA and the relationship between the second included angle alpha 2 and the length of the line OB, the flow separation of the blade is reduced, and the efficiency of the axial flow fan is improved.

Description

Technical Field

[0001] This application relates to the technical field of fans, and more particularly to an axial flow fan and a top-discharge air conditioning outdoor unit. Background Technology

[0002] Axial fans are an important component of air conditioner outdoor units, used to increase the exchange speed between airflow and the outdoor heat exchanger, thereby increasing the heat exchange efficiency of the outdoor heat exchanger.

[0003] In related technologies, axial fans have relatively high operating noise and power consumption, which cannot adequately meet the requirements of air conditioning outdoor units. Summary of the Invention

[0004] In view of the shortcomings of the related technologies, this application provides an axial flow fan and a top-discharge air conditioner outdoor unit. By limiting the forward bending angle and working angle of the blades, the working efficiency of the axial flow fan can be improved while the operating noise of the axial flow fan can be reduced.

[0005] This application provides an axial flow fan, comprising: Wheel hub; Multiple blades are configured, connected to the hub and arranged along the outer periphery of the hub; the blades include: Leading edge, located at the front end in the direction of blade rotation; The trailing edge is located at the rear end in the direction of blade rotation; Define a first straight line that passes through the connection point between the trailing edge and the hub and is perpendicular to the center axis of the hub; Define a second straight line, which is perpendicular to the first straight line and the center axis of the wheel hub. Establish a rectangular coordinate system with the first straight line as the x-axis, the second straight line as the y-axis, the center line of the wheel hub as the z-axis, and the intersection point O of the first straight line, the second straight line and the center line of the wheel hub as the origin; In a rectangular coordinate system, three mutually perpendicular planes are defined: plane xOy, plane yOz, and plane xOz. The projection of the leading edge onto the plane xOy forms the first curve; the projection of the trailing edge onto the plane xOy forms the second curve; Any point A on the first curve is connected to point O by a line OA, and the line OA forms a first angle α1 with the y-axis. Any point B on the second curve forms a line OB with point O, and the line OB forms a second angle α2 with the y-axis. The first included angle α1 satisfies: ; The second included angle α2 satisfies: ; Where A1, A2, B1, B2, D1, C1, and C2 are constants, r1 is the distance from point A to point O, and r2 is the distance from point B to point O.

[0006] In the technical solution, the leading edge is projected onto the xOy plane to form a first curve, and the trailing edge is projected onto the xOy plane to form a second curve. By establishing functional relationships with respect to the distance from point A or point B to the origin O for the first angle α1 formed by any point A on the first curve and the y-axis, and the second angle α2 formed by any point B on the second curve and the y-axis, respectively, the spatial shape of the leading and trailing edges is defined. This allows the blades to better conform to the airflow trajectory when rotating, reducing airflow impact and separation. As a result, while increasing the airflow exchange speed with the outdoor heat exchanger, the operating noise and power consumption can be effectively reduced, enabling the axial fan to better meet the requirements of the outdoor unit of the air conditioner for low noise and low energy consumption.

[0007] In some embodiments of this application, the first included angle α1 satisfies: α1≥4°, α1≤45°; And / or, the second included angle α2 satisfies: α2≥47°, α2≤55°.

[0008] The technical solution defines the specific range of the first included angle α1 and the second included angle α2, further optimizes the angle distribution of the leading edge and trailing edge, ensures the blade's ability to guide airflow to maintain high heat exchange efficiency, and avoids airflow turbulence caused by excessively large or small angles, thereby making the performance of the axial fan more stable to meet the needs of the outdoor unit of the air conditioner.

[0009] In some embodiments of this application, the projection of the leading edge onto the plane yOz forms a third curve; the projection of the trailing edge onto the plane yOz forms a fourth curve; The coordinates of any point on the third curve are (y1, z1), and the third curve can be represented as: ; The coordinates of any point on the fourth curve are (y2, z2); the fourth curve can be represented as: ; Among them, A3, A4, B3, B4, D2, D3, E1, E2, C3, and C4 are constants.

[0010] In the technical solution, by defining the functional expression of the projection curves of the leading edge and trailing edge in the plane yOz, the shape of the leading edge and trailing edge in the plane yOz is designed, thereby optimizing the flow path of airflow in the axial and radial directions of the blade, reducing the impact and separation of airflow at the leading and trailing edges of the blade, reducing airflow noise, and enhancing the blade's ability to guide and drive airflow, increasing the commutation speed, thereby improving heat exchange efficiency and reducing fan power.

[0011] In some embodiments of this application, a first plane is defined, which is parallel to the plane xOz; The blade has a fifth curve in cross-section on the first plane. The two ends of the fifth curve are set at the leading edge and the trailing edge, respectively. The endpoint D of the fifth curve is located on the leading edge, and the endpoint E of the fifth curve is located on the trailing edge. The tangent to the fifth curve at point D forms a fourth angle β1 with the z-axis, and the fourth angle β1 satisfies: ; The tangent to the fifth curve at point E forms a fifth angle β2 with the z-axis, which satisfies: ; Where A5, A6, B5, B6, D4, D5, E3, C5, and C6 are constants, r3 is the distance from point D' (projection point D') on the xOy plane to point O, and r4 is the distance from point E' (projection point E') on the xOy plane to point O.

[0012] In the technical solution, by defining the functional expressions of the fourth included angle β1 and the fifth included angle β2 formed by the tangents of the blade's projection curve in the xOz plane at the endpoints D and E and the z-axis, the tilt angles of the blade's leading and trailing edges in the xOz plane are optimized. This makes the airflow entering and leaving the blade smoother, reduces the noise generated by airflow impact, improves the blade's efficiency in capturing and driving airflow, reduces the operating power of the axial fan, and increases the commutation speed and heat exchange efficiency of the outdoor heat exchanger.

[0013] In some embodiments of this application, the fourth included angle β1 satisfies: ; And / or, the fifth included angle β2 satisfies: ; Where C3≥140, C3≤150; C4≥-410, C4≤-400.

[0014] In the technical solution, by defining the specific functional expressions of the fourth included angle β1 and the fifth included angle β2, the angular changes of the leading edge and trailing edge in the plane xOz are limited, making the interaction between the blades and the airflow more coordinated, reducing the noise caused by airflow disturbance, improving the aerodynamic performance of the axial fan, reducing power consumption, and increasing the heat exchange efficiency of the outdoor heat exchanger.

[0015] In some embodiments of this application, the fourth included angle β1 satisfies: β1≥19°, β1≤38.5°; And / or, the fifth included angle β2 satisfies: β2≥25°, β2≤64.7°.

[0016] In the technical solution, by limiting the specific range of the fourth included angle β1 and the fifth included angle β2, the angles of the leading edge and trailing edge are kept within a suitable working range while ensuring a reasonable blade structure. This reduces airflow impact noise and efficiently promotes airflow, increasing the exchange speed. As a result, the heat exchange effect of the outdoor heat exchanger is enhanced while reducing fan power.

[0017] In some embodiments of this application, the maximum deflection point F of the fifth curve is set close to the leading edge, and the distance L1 from point F to point D and the distance L2 from point D to point E satisfy: L1 = 55%L2.

[0018] In the technical solution, by making the maximum deflection point F of the fifth curve close to the leading edge, and the distance L1 from point F to point D and the distance L2 from point D to point E satisfy L1=55%L2, it is possible not only to optimize the airflow velocity distribution on the blade surface, making the airflow form a reasonable flow state near the leading edge of the blade, reducing eddies and airflow separation, and reducing the noise generated during blade operation, but also to improve the lift characteristics of the blade, improve the efficiency of the axial fan, and reduce power consumption.

[0019] In some embodiments of this application, the blade is defined by forming a central arc line, one end of which is located at the leading edge and the other end of which is located at the trailing edge; the projection point C' of point C on the central arc line onto the plane xOy forms a line OC' with point O, and a third included angle γ is formed between the line OC' and the line OA. The ratio w of the y-coordinate to the z-coordinate of point C in the rectangular coordinate system satisfies: ; Where A7, B7, D6, and C7 are constants, and d is the radian of the third included angle γ.

[0020] In the technical solution, a function expression is established by taking the radian of the third included angle γ as the independent variable and the ratio of the y-coordinate to the z-coordinate of point C on the middle arc as the dependent variable, so as to limit the shape of the middle arc and optimize the pressure distribution on the blade surface, making the airflow on the blade surface smoother, reducing the generation of eddies, thereby reducing the noise caused by airflow disturbance, improving the blade's driving efficiency for airflow, reducing the fan's operating power, and enhancing the heat exchange effect of the outdoor heat exchanger.

[0021] In some embodiments of this application, on the plane xOy, the distance between point C' and point O is r', the distance between the leaf root and point O is r0, and the distance between the leaf tip and point O is r t ; When r'≥r0, r'<0.48r, ; When r'≥0.48r, r'<0.65r, ; When r'≥0.65r, r'<0.83r, ; When r'≥0.83r, r'≤r t hour, .

[0022] In the technical solution, specific functional expressions for the dependent variable w and the independent variable d are given for the range of values ​​of the distance r' from point C' on the middle arc to the origin O. This allows for the adjustment of the shape of the middle arc according to the airflow characteristics of the blade at different radius positions, so that the shape of each part of the blade is adapted to the airflow characteristics, reducing local airflow turbulence, reducing the operating noise of the axial fan, improving the aerodynamic efficiency of the fan, reducing power loss, and improving the overall performance of the outdoor unit of the air conditioner.

[0023] In addition, this application also provides a top-discharge air conditioning outdoor unit, comprising: The housing has an air inlet and an air outlet. The air inlet is located on the periphery of the housing, and the air outlet is located on the top of the housing. The outdoor heat exchanger is located inside the casing and is used to exchange heat with the air passing through it; the windward side of the outdoor heat exchanger faces the air inlet. The compressor is located inside the casing and on the leeward side of the outdoor heat exchanger; An axial fan, which is the aforementioned axial fan; the axial fan is located inside the housing, above the compressor and near the air outlet; Drive motor, used to drive the axial fan.

[0024] In the technical solution, the axial fan generates less noise when it is running, has higher airflow efficiency, accelerates the heat exchange speed between the air and the outdoor heat exchanger, reduces ineffective energy consumption, and lowers the power of the drive motor, so that the axial fan can better meet the needs of the outdoor unit of the air conditioner.

[0025] In the above embodiments, an axial fan and a top-discharge air conditioner outdoor unit define the shape of the leading and trailing edges by limiting the variation law of the blade's forward bending angle and working angle with the blade radius. This improves the radial aerodynamic load distribution of the blades, allowing the airflow to flow in and out more smoothly and efficiently. This effectively reduces the aerodynamic noise caused by airflow separation and vortex shedding, and reduces the extra power consumed by the axial fan to overcome poor airflow. It also makes the blades fit the airflow trajectory better when rotating, reducing airflow impact and separation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of one embodiment of the axial fan in this application; Figure 2 This is a structural schematic diagram of another embodiment of the axial fan in this application from another angle; Figure 3 This is a schematic diagram of the blades in a rectangular coordinate system in one embodiment of the axial fan in this application; Figure 4 This is a schematic diagram of the projection of the blades onto the plane xOy in one embodiment of the axial fan in this application; Figure 5 This is a schematic diagram of the projection curves of the blade tip and blade root on the plane xOy in one embodiment of the axial fan in this application; Figure 6 This is a schematic diagram of the projection pattern of the blades on the plane yOz in one embodiment of the axial fan in this application; Figure 7 This is a schematic cross-sectional view of the blades on the first plane in one embodiment of the axial fan in this application; Figure 8 This is a schematic diagram of the fourth and fifth included angles in one embodiment of the axial flow fan in this application; Figure 9 It is a tip vortex cloud diagram of an axial fan in related technologies; Figure 10 This is a tip vortex cloud diagram of an embodiment of the axial fan in this application; Figure 11 This is a schematic diagram of five mid-arc lines in one embodiment of the axial flow fan in this application; Figure 12 This is a comparison diagram of the static pressure efficiency of an embodiment of the axial fan in this application and axial fans in related technologies; Figure 13 This is a comparison chart of the noise levels of an embodiment of the axial fan in this application and axial fans in related technologies.

[0027] In the diagram, 100 represents the blade; 200 represents the hub. 110. Leading edge; 120. Tail edge; 130. Leaf tip; 140. Leaf base; 101. First curve; 102. Second curve; 103. Third curve; 104. Fourth curve; 105. Fifth curve; 106. First intermediate arc; 107. Second intermediate arc; 108. Third intermediate arc; 109. Fourth intermediate arc; 1010. Fifth intermediate arc; 1011. Second projection intermediate arc; 1012. Third projection intermediate arc; 1013. Fourth projection intermediate arc. Detailed Implementation

[0028] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0029] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0030] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0031] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0032] like Figure 1 and Figure 2 As shown, this application provides a specific embodiment of an axial flow fan.

[0033] like Figure 1 and Figure 2 As shown, the axial fan includes a hub 200, which is connected to the rotating shaft of a motor so that the motor drives the axial fan to rotate; the hub 200 defines a central axis, and the axial fan rotates about the central axis.

[0034] like Figure 1 and Figure 2 As shown, the axial fan includes blades 100, one end of which is connected to the hub 200, and the other end of which extends away from the hub 200; multiple blades 100 are provided, and the multiple blades 100 are arranged along the outer periphery of the hub 200.

[0035] To ensure the stability of the axial fan during rotation, multiple blades 100 are evenly distributed along the circumference of the hub 200 to ensure that the axial fan is subjected to uniform force and to prevent tilting and shaking during rotation.

[0036] In some embodiments, the number of blades 100 is set to six, and the six blades 100 are evenly distributed on the outer periphery of the hub 200.

[0037] like Figures 1-3 As shown, the blade 100 includes a blade tip 130, which is disposed away from the hub 200 relative to the blade root 140. The blade tip 130 and the blade root 140 are disposed opposite each other in the radial direction of the axial flow fan. The blade tip 130 and the blade root 140 are respectively located at opposite ends of the blade 100 in the radial direction of the axial flow fan.

[0038] like Figures 1-3 As shown, the blade 100 includes a blade root 140, which is connected to the hub 200.

[0039] like Figures 1-3 As shown, the blade 100 includes a leading edge 110, which is located at the front end of the blade 100 in the direction of rotation and connects the blade tip 130 and the blade root 140.

[0040] The leading edge 110 does not extend straight along the radial direction of the axial fan. Instead, the leading edge 110 is typically curved backward along the direction of rotation of the blade 100 so that the leading edge 110 can smoothly cut the oncoming fluid and show the flow of the cut fluid along the top and bottom of the blade 100, thereby minimizing drag, avoiding flow separation, and accommodating a wider angle of attack of the incoming flow.

[0041] In some embodiments, the leading edge 110 has a sharp corner at one end near the blade tip 130. The sharp corner design can reduce the contact area between the leading edge 110 and the air, thereby reducing air resistance. The middle portion of the leading edge 110 is bent backward along the rotation direction of the blade 100 to optimize the matching relationship between the oncoming airflow and the leading edge 110 and suppress airflow separation.

[0042] like Figures 1-3 As shown, the blade 100 includes a trailing edge 120, which is located at the rear end of the blade 100 in the direction of rotation and connects the blade tip 130 and the blade root 140. The trailing edge 120 is the part where the airflow leaves the blade 100, and it is prone to generating unstable vortices, which is one of the main sources of aerodynamic noise.

[0043] The trailing edge 120 does not extend straight along the radial direction of the axial fan, so that the two fluids flowing from the upper and lower surfaces of the blade 100 can merge, avoiding the generation of eddies and pressure drag, ensuring that energy is efficiently transferred to the fluid, optimizing the fluid flow state, and significantly improving the lift-to-drag ratio and operating efficiency of the blade 100.

[0044] In some embodiments, the end of the trailing edge 120 near the blade tip 130 bends forward along the rotation direction of the blade 100, while the other portion of the trailing edge 120 bends backward along the rotation direction of the blade 100.

[0045] Define a first straight line that passes through the connection point between the trailing edge 120 and the hub 200 and is perpendicular to the central axis of the hub 200.

[0046] Define a second straight line, which is perpendicular to the first straight line and the centerline of hub 200.

[0047] like Figure 3As shown, a rectangular coordinate system is established with the first straight line as the x-axis, the second straight line as the y-axis, the central axis of the hub 200 as the z-axis, and the intersection point O of the first straight line, the second straight line and the central axis of the hub 200 as the origin.

[0048] In a rectangular coordinate system, three mutually perpendicular planes are defined: plane xOy, plane yOz, and plane xOz.

[0049] like Figure 4 As shown, the projection of the leading edge 110 onto the plane xOy forms the first curve 101. Point A and point O on the first curve 101 are connected by a line OA, and the line OA and the y-axis form a first angle α1. The first angle α1 is also the forward bending angle of the leading edge 110. The angle of the first angle α1 determines the air intake state of the leading edge 110 and has a significant impact on the air delivery performance of the axial flow fan.

[0050] In some embodiments, the first included angle α1 satisfies: α1≥4°, α1≤45°, so as to ensure that the blade 100 has the ability to guide the airflow to maintain a high heat exchange efficiency, and to avoid airflow turbulence caused by excessively large or small angles, so that the performance of the axial fan can more stably meet the needs of the outdoor unit of the air conditioner.

[0051] If α1 < 4°, the leading edge 110 is too straight, and its curvature cannot smoothly guide the airflow. This can easily lead to flow separation when the airflow impacts the leading edge 110, generating eddies and turbulence, thereby increasing air resistance and aerodynamic noise. At the same time, the narrow intake angle of attack will reduce adaptability, making the air delivery performance of the axial fan unstable and reducing the heat exchanger's heat exchange efficiency.

[0052] If α1 > 45°, the leading edge 110 will bend excessively backward. Although this can increase the guiding effect on the airflow, it can easily lead to a reduction in the effective working area of ​​the blade 100. Excessive bending will make the airflow path along the surface of the blade 100 too long, increasing friction loss. At the same time, it may form a new flow separation zone at the blade tip 130, reducing the working efficiency of the axial fan and leading to increased energy consumption.

[0053] It should be noted that the value of the first included angle α1 is different when point A is in different positions. Specifically, the value of the first included angle α1 is the largest when point A is located at the connection point H between the leading edge 110 and the leaf root 140; and the value of the first included angle α1 is the smallest when point A is located at the connection point K between the leading edge 110 and the leaf tip 130.

[0054] In this application, by taking the first included angle α1 as the dependent variable and the distance r1 from point A to point O as the independent variable, a functional expression of α1 and r1 is established to limit the shape of the leading edge 110, so that the blade 100 can better fit the airflow trajectory when rotating, reducing airflow impact and separation phenomena.

[0055] Specifically, the first included angle α1 satisfies: ; Where A1, B1, and C1 are constants, and r1 is the distance from point A to point O.

[0056] The range of values ​​for A1 is: A1≥0.85, A1≤1.15; the range of values ​​for B1 is: B1≥0.2, B1≤0.3; the range of values ​​for C1 is: C1≥60, C1≤75.

[0057] In some embodiments, A1 is 1, B1 is 0.229, and C1 is 69, that is... This improves the intake conditions of the leading edge 110, increases the working efficiency of the blade 100, and reduces intake noise. It ensures that the airflow can contact the leading edge 110 at appropriate angles of attack at different radii from the blade root 140 to the blade tip 130, thereby efficiently transferring rotational kinetic energy to the air. This avoids sudden separation of the airflow or the generation of turbulence at the leading edge 110 due to improper angles of attack, and reduces impact noise and flow loss.

[0058] like Figure 4 As shown, the projection of the trailing edge 120 onto the plane xOy forms a second curve 102. Point B of the second curve 102 and point O form a line OB. The line OB and the y-axis form a second included angle α2. The second included angle α2 is the working angle of the blade 100. The second included angle α2 determines the projected area of ​​the blade 100 on the plane xOy, and also affects the size of the first included angle α1, thereby affecting the air volume and air resistance of the axial flow fan.

[0059] It should be noted that the value of the second included angle α2 is different when point B is in different positions. Specifically, the value of the second included angle α2 is the largest when point B is located at the connection point G between the trailing edge 120 and the leaf root 140; and the value of the second included angle α2 is the smallest when point B is located at the connection point K' between the trailing edge 120 and the leaf tip 130.

[0060] In some embodiments, the second included angle α2 satisfies: α2≥47°, α2≤55°, so as to ensure that the blade 100 has the ability to guide the airflow to maintain a high heat exchange efficiency, and to avoid airflow turbulence caused by excessively large or small angles, thereby making the performance of the axial fan more stable to meet the needs of the outdoor unit of the air conditioner.

[0061] If α2 < 47°, the working angle of the trailing edge 120 is too small, which will reduce the effective projected area of ​​the blade 100 on the plane xOy. The shape of the blade 100 is too "upright", resulting in insufficient contact range between the blade 100 and the airflow, and a reduction in the air volume. The airflow does not converge smoothly at the trailing edge 120, which can easily form eddies and pressure drag, increase energy consumption and noise, and also disrupt the overall aerodynamic balance of the blade 100, affecting the fan's operating efficiency and stability.

[0062] If α2 > 55°, the working angle of the trailing edge 120 is too large, and the blades 100 are too "flat" in the plane of rotation. Although the projected area increases, it will cause the flow channel between the blades 100 to become narrow and tortuous, increasing the frictional resistance and pressure resistance of the airflow. This will require the axial fan to consume more power to overcome the resistance. It will also easily cause vortex shedding and airflow separation at the trailing edge 120, generating huge aerodynamic noise. It may also cause vibration and shaking during the operation of the axial fan, reducing the air delivery efficiency and the stability of the axial fan operation.

[0063] In this application, by taking the second included angle α2 as the dependent variable and the distance r2 from point B to point O as the independent variable, a functional expression of α2 and r2 is established to limit the shape of the trailing edge 120, so that the blade 100 can better conform to the airflow trajectory when rotating, reducing airflow impact and separation phenomena.

[0064] Specifically, the second included angle α2 satisfies: ; Where A2, B2, D1, and C2 are constants, and r2 is the distance from point B to point O.

[0065] The range of values ​​for A2 is: A2≥2.5, A2≤3.5; the range of values ​​for B2 is: B2≥0.0015, B2≤0.0025; the range of values ​​for D1 is: D1≥0.45, D1≤0.55; the range of values ​​for C2 is: C2≥15, C2≤25.

[0066] In some embodiments, A2 is 3, B2 is 0.0021, D1 is 0.4872, and C2 is 21, that is... This design allows the airflow from the upper and lower surfaces of the blade 100 to smoothly converge at the trailing edge 120, weakening the intensity and size of the vortex at the trailing edge 120 and effectively suppressing the generation of high-frequency noise. Simultaneously, it reduces airflow resistance, further lowering the fan's power consumption; it also improves airflow exit conditions on the blade 100, reducing vortex shedding and thus lowering wake noise.

[0067] It should be noted that, as Figure 5As shown, the projection curve of the leaf tip 130 onto the xOy plane is the first leaf tip curve 131, and the projection curve of the leaf root 140 onto the xOy plane is the first leaf root curve 141. On the xOy plane, the point on the first leaf tip curve 131 has the largest distance r0 from the origin O, and the point on the first leaf root curve 141 has the largest distance r from the origin O. t Therefore, the range of values ​​for r1 is minimized, and thus, r1 ≥ r0. t The range of values ​​for r2 satisfies: r2 ≤ r0, r2 ≥ r t .

[0068] In some embodiments, the distance r0 from the first leaf tip curve 131 to the origin O is 372, and the distance r from the first leaf root curve 141 to the origin O is... t The value is 115, that is, r1≤115, r1≥372; r2≤115, r2≥372.

[0069] like Figure 6 As shown, the projection of the leading edge 110 onto the plane yOz forms a third curve 103, and the coordinates of any point on the third curve 103 are (y1, z1). The third curve 103 can be represented as: ; A3, B3, D2, E1, and C3 are constants.

[0070] The range of values ​​for A3 is: A3≥0.5, A3≤3.5; the range of values ​​for B3 is: B3≥0, B3≤3.2; the range of values ​​for D2 is: D2≥-0.1, D2≤0.3; the range of values ​​for E1 is: E1≥-1, E1≤26; the range of values ​​for C3 is: C3≥-1, C3≤913.

[0071] In some embodiments, the third curve 103 is To improve the static pressure resistance of blade 100.

[0072] In other embodiments, the third curve 103 is not entirely represented by a single functional relationship, but rather by different functional expressions corresponding to the numerical range of the distance y1 from a point on the third curve 103 to the z-axis. That is, the third curve 103 can be considered as a piecewise function.

[0073] Specifically, when y1≥115 and y1≤126, When y1 > 126 and y1 ≤ 372, .

[0074] Right now By using different function expressions corresponding to the distance y1 from the point on the third curve 103 to the z-axis, the flow path of the airflow in the axial and radial directions of the blade 100 is optimized, the impact and separation of the airflow at the leading edge 110 are reduced, the airflow noise is reduced, and the ability of the blade 100 to guide and drive the airflow is enhanced, the commutation speed is increased, thereby improving the heat exchange efficiency and reducing the fan power.

[0075] like Figure 6 As shown, the projection of the trailing edge 120 onto the plane yOz forms a fourth curve 104, and the coordinates of any point on the fourth curve 104 are (y2, z2); the fourth curve 104 can be represented as: ; Among them, A4, B4, D3, E2, and C4 are constants.

[0076] The range of values ​​for A4 is: A4≥0.5, A4≤4.5; the range of values ​​for B4 is: B4≥0, B4≤4; the range of values ​​for D3 is: D3≥-1, D3≤2; the range of values ​​for E2 is: E2≥-1, E2≤202; the range of values ​​for C4 is: C4≥220, C4≤4660.

[0077] In some embodiments, the fourth curve 104 is This reduces the torque of the axial fan and improves its efficiency.

[0078] In other embodiments, the fourth curve 104 is not entirely represented by a single functional relationship, but rather by different functional expressions corresponding to the numerical range of the distance y2 from a point on the fourth curve 104 to the z-axis. That is, the fourth curve 104 can be considered as a piecewise function.

[0079] Specifically, when y2≥115 and y2≤130, When y2 > 130 and y2 ≤ 340, When y2 > 340 and y2 ≤ 372, .

[0080] Right now This optimizes the airflow path in the axial and radial directions of the blade 100, reduces the impact and separation of airflow at the trailing edge, lowers airflow noise, and enhances the guiding and driving ability of the blade 100 to improve the commutation speed, thereby improving heat exchange efficiency and reducing fan power.

[0081] It should be noted that the plane yOz is also the meridional plane of the axial fan.

[0082] Define a first plane, which is parallel to the xOz plane; like Figure 7As shown, the blade 100 has a cross-sectional shape defined on the first plane, forming a fifth curve 105. The fifth curve 105 is the arc of the blade 100 in the cross-sectional shape on the first plane. The two ends of the fifth curve 105 are set corresponding to the leading edge 110 and the trailing edge 120. The endpoint D of the fifth curve 105 is located on the leading edge 110, and the endpoint E of the fifth curve 105 is located on the trailing edge 120.

[0083] like Figure 8 As shown, the tangent of the fifth curve 105 at point D forms a fourth angle β1 with the z-axis. The fourth angle β1 will affect the acceleration or deceleration of the airflow when it passes through the blade 100, and affect the intensity and path of the leakage flow at the blade tip 130.

[0084] The fourth included angle β1 satisfies: β1≥19°, β1≤38.5°, so that while ensuring the reasonable structure of blade 100, the angle of the leading edge 110 is within a suitable working range, which reduces airflow impact noise and can efficiently drive airflow and improve the exchange speed, thereby reducing fan power while enhancing the heat exchange effect of the outdoor heat exchanger.

[0085] If the fourth included angle β1 < 19°, the leading edge 110 is too "flat" in the axial direction (z-axis direction), with insufficient tilt, which easily leads to a weakened ability of the leading edge 110 of the blade 100 to "capture" the oncoming airflow, and a reduction in the effective working area. Too small an tilt angle will make the angle of airflow impact on the pressure surface of the blade 100 too steep, which can easily cause airflow separation and flow loss, and at the same time, it cannot effectively guide the airflow, thereby reducing the fan's working efficiency, wind pressure and air volume, and may increase intake noise.

[0086] If the fourth included angle β1 > 38.5°, the leading edge 110 will be too "upright" in the axial direction, with excessive tilt. Although this can increase the guiding effect of the leading edge 110 on the airflow, it will result in an excessively large axial projected area of ​​the blade 100, significantly increasing the wind resistance in the forward direction and the bending stress of the blade 100 itself. An excessively large tilt angle will also make the blade root 140 too thick, affecting the smooth transition of airflow from the blade root 140 to the blade tip 130, and easily generating strong leakage vortices in the blade tip 130 region, increasing vortex noise and aerodynamic losses.

[0087] In this application, by taking the fourth included angle β1 as the dependent variable and the distance r3 from the projection point D' of point D on the plane xOy to point O as the dependent variable, a functional expression for β1 and r3 is established to limit the tilt angle of the leading edge 110 in the xOz plane, so that the airflow enters the blade 100 more smoothly, reducing the noise generated by the airflow impact, while improving the blade 100's capture and propulsion efficiency of the airflow, reducing the operating power of the axial fan, and increasing the flow rate and heat exchange efficiency of the outdoor heat exchanger.

[0088] Specifically, the fourth included angle β1 satisfies: ; Where A5, B5, D4, and C5 are constants, and r3 is the distance from point O to point D', the projection point of point D on the plane xOy; the range of A5 is: A5≥-1.5, A5≤-0.56; the range of B5 is: B5≥0, B5≤0.01; the range of D4 is: D4≥1, D4≤2; and the range of C5 is: C5≥140, C5≤150.

[0089] In some embodiments, This design aims to make the airflow smoother when it enters the blades 100, reduce the noise generated by the airflow impact, improve the efficiency of the blades 100 in capturing and driving the airflow, reduce the operating power of the axial fan, and increase the exchange speed and heat exchange efficiency of the outdoor heat exchanger.

[0090] like Figure 9 As shown, the vorticity loss at the blade tip 130° is relatively large in related technologies; for example... Figure 10 As shown, the vortex loss at the blade tip 130 is small in this application.

[0091] like Figure 8 As shown, the tangent of the fifth curve 105 at point E forms a fifth angle β2 with the z-axis. The fifth angle β2 will affect the acceleration or deceleration of the airflow when it passes through the blade 100, and affect the intensity and path of the leakage flow at the blade tip 130.

[0092] The fifth included angle β2 satisfies: β2≥25°, β2≤64.7°, so that while ensuring the reasonable structure of the blade 100, the angle of the trailing edge 120 is within a suitable working range. This reduces airflow impact noise and efficiently drives the airflow, increasing the exchange speed. Thus, while reducing fan power, it enhances the heat exchange effect of the outdoor heat exchanger.

[0093] If the fifth included angle β2 < 25°, the trailing edge 120 is too "flat" in the axial direction, which can easily lead to insufficient axial velocity component and excessive circumferential velocity component when the airflow leaves the blade 100. That is, the airflow has a large "rotation" or "vortex", which fails to effectively convert rotational kinetic energy into the required axial kinetic energy. This "twisting" outlet airflow not only has large energy loss and low efficiency, but also easily impacts components such as heat exchangers, generating aerodynamic noise and reducing the overall heat exchange efficiency of the system.

[0094] If the fifth included angle β2 > 64.7°, the trailing edge 120 will be too "upright" in the axial direction, and may even be bent forward, which will make the flow channel at the trailing edge 120 of the blade 100 abnormally narrow and rapid, increasing the frictional resistance and pressure resistance of the airflow. The airflow will be difficult to merge smoothly when leaving the blade 100, and a large-scale, unstable vortex street will easily be generated behind the trailing edge 120.

[0095] In this application, by taking the fifth included angle β2 as the dependent variable and the distance r4 from the projection point E' of point E on the plane xOy to point O as the dependent variable, a functional expression for β2 and r4 is established to limit the tilt angle of the trailing edge 120 in the xOz plane, so that the airflow leaves the blade 100 more smoothly, reducing the noise generated by the airflow impact, while improving the capture and propulsion efficiency of the blade 100 for the airflow, reducing the operating power of the axial fan, and increasing the flow rate and heat exchange efficiency of the outdoor heat exchanger.

[0096] Specifically, the fifth included angle β2 satisfies: ; Where A6, B6, D5, E3, and C6 are constants, and r4 is the distance from point O to point E', the projection point of point E on the plane xOy.

[0097] In some embodiments, the fifth included angle β2 satisfies: This design aims to improve the coordination between the blades 100 and the airflow, reduce noise caused by airflow disturbance, enhance the aerodynamic performance of the axial fan, reduce power consumption, and increase the heat exchange efficiency of the outdoor heat exchanger.

[0098] like Figure 8 As shown, the maximum deflection point F of the fifth curve 105 is set close to the leading edge 110. The distance L1 from point F to point D and the distance L2 from point D to point E satisfy: L1 = 55%L2, in order to optimize the airflow velocity distribution on the surface of blade 100, so that the airflow forms a reasonable flow state near the leading edge 110 of blade 100, reducing eddies and airflow separation, reducing the noise generated when blade 100 is running, and also improving the lift characteristics of blade 100, improving the efficiency of axial fan, and reducing power consumption.

[0099] The blade 100 has a central arc defined along its rotation direction, with one end of the central arc located at the leading edge 110 and the other end located at the trailing edge 120. The central arc determines the bending angle of the blade 100, thereby affecting the degree of airflow turning and energy transfer efficiency.

[0100] The projection of point C on the middle arc onto the plane xOy is C', which forms a line OC' with point O. A third angle γ is formed between the line OC' and the line OA.

[0101] In some embodiments, γ ≥ 4°, γ ≤ 55°.

[0102] In this application, a function expression is established with the radian of the third included angle γ as the independent variable and the ratio w of the y-coordinate to z-coordinate of point C on the middle arc as the dependent variable to limit the shape of the middle arc, thereby optimizing the pressure distribution on the surface of the blade 100, making the airflow on the surface of the blade 100 smoother, reducing the generation of eddies, thereby reducing the noise caused by airflow disturbance, and also improving the driving efficiency of the blade 100 on the airflow, reducing the operating power of the fan, and enhancing the heat exchange effect of the outdoor heat exchanger.

[0103] Specifically, the ratio w of the y-coordinate to the z-coordinate of point C in the rectangular coordinate system satisfies: ; Where A7, B7, D6, and C7 are constants, and d is the radian of the third included angle γ.

[0104] The range of values ​​for A7 is: A7≥0, A7≤0.55; the range of values ​​for B7 is: B7≥-0.65, B7≤0.9; the range of values ​​for D6 is: D6≥-0.45, D6≤1.2; the range of values ​​for C7 is: C7≥0, C7≤0.5.

[0105] On the plane xOy, the distance between point C' and point O is r', where r' ≥ r0 and r' ≤ r t .

[0106] The relationship between the ratio w and the radian d is a piecewise function of the distance r' between point C' and point O. Based on the airflow characteristics of the blade 100 at different radius positions, the shape of the middle arc is adjusted so that the shape of each part of the blade 100 is adapted to the airflow characteristics, reducing local airflow turbulence, reducing the operating noise of the axial fan, improving the aerodynamic efficiency of the fan, reducing power loss, and improving the overall performance of the outdoor unit of the air conditioner.

[0107] Specifically, when r'≥r0 and r'<0.48r, ; When r'≥0.48r, r'<0.65r, ; When r'≥0.65r, r'<0.83r, ; When r'≥0.83r, r'≤r t hour, .

[0108] By considering different cases of the distance r' from point C' on the middle arc to the origin O, a specific functional expression for the ratio w and the radian d is given. This allows for adjustment of the middle arc shape according to the airflow characteristics of the blade 100 at different radius positions, so that the shape of each part of the blade 100 is adapted to the airflow characteristics, reducing local airflow turbulence, lowering the operating noise of the axial fan, improving the aerodynamic efficiency of the fan, reducing power loss, and enhancing the overall performance of the outdoor unit of the air conditioner.

[0109] In some embodiments, such as Figure 5 and Figure 11 As shown, the blade 100 is divided into five sections along its radial direction, and the mid-arc line is the curve connecting the centers of the inscribed circles of the airfoil in each section; that is, the blade 100 includes five mid-arc lines, and the directions of the five mid-arc lines from the blade root 140 to the blade tip 130 are respectively called: the first mid-arc line 106, the second mid-arc line 107, the third mid-arc line 108, the fourth mid-arc line 109 and the fifth mid-arc line 1010.

[0110] like Figure 5 As shown, among the five intermediate arcs, by adjusting the fourth intermediate arc 109 to a straight line and designing the upward curves at both ends of the fifth intermediate arc 1010, the blade tip 130 is flanged, achieving a maximum deflection of 55% of the blade chord. When the fourth intermediate arc becomes a straight line, the geometric angle of attack distribution from the leading edge 110 to the trailing edge 120 of the blade 100 is reconstructed. The straight intermediate arc forms a quasi-symmetrical airfoil with near-zero curvature at the blade tip 130, significantly reducing the local aerodynamic angle of attack in this region and suppressing the airflow separation originally caused by excessive curvature of the intermediate arc. The upward curves at both ends of the fifth intermediate arc form a high-pressure barrier on the blade back side, suppressing the lateral migration of the leaked flow. After the intermediate arc optimization, the vortex intensity at the fan blade tip 130 is significantly reduced.

[0111] like Figure 5 As shown, the projections of the five mid-arc lines on the xOy plane are the first projected mid-arc line, the second projected mid-arc line 1011, the third projected mid-arc line 1012, the fourth projected mid-arc line 1013, and the fifth projected mid-arc line, respectively. The first projected mid-arc line, the second projected mid-arc line 1011, the third projected mid-arc line 1012, the fourth projected mid-arc line 1013, and the fifth projected mid-arc line are arranged radially along the blade 100. The first projected mid-arc line coincides with the first blade root curve 141, and the fifth projected mid-arc line coincides with the first blade tip curve 131.

[0112] like Figure 12 As shown, compared with the six-blade axial fan in this application and the four-blade axial fan in related technologies, the static pressure efficiency of the axial fan in this application is improved by 5% in the flow coefficient range of [0.275-0.35].

[0113] like Figure 13As shown, comparing the six-blade axial fan in this application with the four-blade axial fan in related technologies, within the flow coefficient range of [0.275-0.35], the noise of the axial fan in this application is the same or slightly lower than that of the four-blade axial fan in related technologies. When rotating at the same speed, the motor power decreases by 6.8%.

[0114]

[0115] In the aforementioned axial flow fan, the airflow can flow in and out more smoothly and efficiently, thereby effectively reducing the aerodynamic noise caused by airflow separation and vortex shedding, and reducing the extra power consumed by the axial flow fan to overcome poor airflow, so that the blades 100 rotate more closely to the airflow trajectory, reducing airflow impact and separation.

[0116] Based on the aforementioned axial fan, this application also provides a top-discharge air conditioner outdoor unit, which includes a casing, an air inlet formed on the casing, through which air enters the casing; the air inlet is located on the peripheral wall of the casing; an air outlet is formed on the casing, through which air inside the casing is output to the outside of the casing; and the air outlet is located at the top of the casing.

[0117] A top-discharge air conditioner outdoor unit includes an outdoor heat exchanger, which is located inside the unit casing and is used to exchange heat with the air passing through it. The windward side of the outdoor heat exchanger faces the air inlet, and the leeward side faces the interior of the unit casing. The outdoor heat exchanger extends along the peripheral wall of the unit casing to maximize its surface area within the limited space of the casing, thereby increasing the efficiency of the top-discharge air conditioner outdoor unit.

[0118] The outdoor unit of a top-discharge air conditioner includes a compressor, which is located inside the casing and on the leeward side of the outdoor heat exchanger.

[0119] The outdoor unit of a top-discharge air conditioner includes an axial fan, which is located inside the casing and at the top of the casing. The axial fan is positioned close to the air outlet to increase the airflow speed.

[0120] The outdoor unit of a top-discharge air conditioner includes a drive motor, which drives an axial fan to operate so that air enters the casing through the air inlet, exchanges heat with the outdoor heat exchanger, and is then output to the outside of the casing through the air outlet.

[0121] Among the aforementioned top-discharge air conditioning outdoor units, the axial fan operates with low noise and large air volume, the drive motor has low power, and the outdoor heat exchanger has good heat exchange effect.

[0122] It should be noted that the aforementioned axial flow fan is not limited to use in top-discharge air conditioner outdoor units, but can also be used in vertical air conditioner indoor units and other equipment, which will not be elaborated here.

[0123] Finally, it should be noted that 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0124] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. An axial flow fan, characterized in that, include: Wheel hub; The blades are configured in multiples, and the multiple blades are connected to the hub and arranged along the outer periphery of the hub; The blade includes: Leading edge, located at the front end in the direction of blade rotation; Trailing edge, located at the rear end in the direction of blade rotation; Define a first straight line that passes through the connection point between the trailing edge and the hub and is perpendicular to the center axis of the hub; Define a second straight line, which is perpendicular to the first straight line and the center axis of the wheel hub, respectively; A rectangular coordinate system is established with the first straight line as the x-axis, the second straight line as the y-axis, the central axis of the wheel hub as the z-axis, and the intersection point O of the first straight line, the second straight line, and the central axis of the wheel hub as the origin. In the rectangular coordinate system, three mutually perpendicular planes are defined: plane xOy, plane yOz, and plane xOz. The projection of the leading edge onto the plane xOy forms a first curve; the projection of the trailing edge onto the plane xOy forms a second curve; Any point A on the first curve is connected to point O by a line OA, and the line OA forms a first angle α1 with the y-axis; Any point B on the second curve forms a line OB with point O, and the line OB forms a second included angle α2 with the y-axis; The first included angle α1 satisfies: ； The second included angle α2 satisfies: ; Where A1, A2, B1, B2, D1, C1, and C2 are constants, r1 is the distance from point A to point O, and r2 is the distance from point B to point O; The first included angle α1 satisfies: α1≥4°, α1≤45°; And / or, the second included angle α2 satisfies: α2≥47°, α2≤55°.

2. The axial flow fan according to claim 1, characterized in that, The projection of the leading edge onto the plane yOz forms a third curve; the projection of the trailing edge onto the plane yOz forms a fourth curve; The coordinates of any point on the third curve are (y1, z1), and the third curve can be represented as: ； The coordinates of any point on the fourth curve are (y2, z2); the fourth curve can be represented as: ; Among them, A3, A4, B3, B4, D2, D3, E1, E2, C3, and C4 are constants.

3. The axial flow fan according to claim 1, characterized in that, Define a first plane, which is parallel to the plane xOz; The blade has a fifth curve in cross-section on the first plane. The two ends of the fifth curve are set corresponding to the leading edge and the trailing edge, wherein the endpoint D of the fifth curve is located on the leading edge and the endpoint E of the fifth curve is located on the trailing edge. The tangent to the fifth curve at point D forms a fourth included angle β1 with the z-axis, and the fourth included angle β1 satisfies: ； The tangent to the fifth curve at point E forms a fifth angle β2 with the z-axis, and the fifth angle β2 satisfies: ； Where A5, A6, B5, B6, D4, D5, E3, C5, and C6 are constants, r3 is the distance from point D' (projection point D') on the xOy plane to point O, and r4 is the distance from point E' (projection point E') on the xOy plane to point O.

4. The axial flow fan according to claim 3, characterized in that, The fourth included angle β1 satisfies: ； And / or, the fifth included angle β2 satisfies: ; Where C3≥140, C3≤150; C4≥-410, C4≤-400.

5. The axial flow fan according to claim 3, characterized in that, The fourth included angle β1 satisfies: β1≥19°, β1≤38.5°; And / or, the fifth included angle β2 satisfies: β2≥25°, β2≤64.7°.

6. The axial flow fan according to claim 3, characterized in that, The maximum deflection point F of the fifth curve is set close to the leading edge, and the distance L1 from point F to point D and the distance L2 from point D to point E satisfy: L1 = 55%L2.

7. The axial flow fan according to claim 1, characterized in that, The blade is defined by a central arc line, one end of which is located at the leading edge and the other end of which is located at the trailing edge; the projection point C' of point C on the central arc line onto the plane xOy forms a line OC' with point O, and a third included angle γ is formed between the line OC' and the line OA. Wherein, the ratio w of the y-coordinate to the z-coordinate of point C in the rectangular coordinate system satisfies: ; Where A7, B7, D6, and C7 are constants, and d is the radian of the third included angle γ.

8. The axial flow fan according to claim 7, characterized in that, On the plane xOy, the distance between point C' and point O is r', the distance between the leaf root and point O is r0, and the distance between the leaf tip and point O is r t ; When r'≥r0, r'<0.48r, ; When r'≥0.48r, r'<0.65r, ; When r'≥0.65r, r'<0.83r, ; When r'≥0.83r, r'≤r t hour, .

9. A top-discharge outdoor unit for an air conditioner, characterized in that, include: A housing having an air inlet and an air outlet, the air inlet being located on the peripheral wall of the housing and the air outlet being located on the top of the housing; An outdoor heat exchanger is disposed inside the housing and is used to exchange heat with the air passing through it; the windward side of the outdoor heat exchanger faces the air inlet. A compressor, wherein the compressor is disposed within the housing and located on the leeward side of the outdoor heat exchanger; An axial fan, as described in any one of claims 1-8; the axial fan is disposed inside the housing, and the axial fan is located above the compressor and close to the air outlet; A drive motor is used to drive the axial fan to operate.

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