Fan and refrigeration equipment

Abstract

The invention discloses a draught fan and refrigeration equipment, the draught fan comprises an air duct, a first impeller and a second impeller, the first impeller is rotationally installed in the air duct, the first impeller comprises a first hub and first blades arranged on the first hub, the installation angle W1 of the first blades is larger than or equal to 25 degrees and smaller than or equal to 42 degrees; and the second impeller is rotationally installed in the air duct and comprises a second hub and second blades arranged on the second hub, the installation angle W2 of the second blades is larger than or equal to 25 degrees and smaller than or equal to 40 degrees, and W1-W2 is smaller than or equal to 8 degrees. According to the fan provided by the invention, the air volume is effectively increased on the premise that the rotating speed is not excessively increased or the diameter of the impeller is not increased, the noise is prevented from being remarkably increased due to the too high rotating speed or the too large impeller, the phenomena of turbulence and boundary layer separation are reduced, the static pressure efficiency is improved, and therefore the operation noise is reduced while large-air-volume output is achieved; and the overall pneumatic performance and energy efficiency of the fan are improved.

Description

Technical Field

[0001] This application relates to the field of refrigeration equipment technology, and more specifically, to a fan and refrigeration equipment. Background Technology

[0002] Currently, the heat pump and air conditioning industries have increasingly higher requirements for the high air volume and low noise performance of fans, and traditional single-impeller axial flow fans are the mainstream application equipment in this field. However, traditional single-impeller axial flow fans have obvious technical defects. Their air volume improvement mainly relies on increasing the rotational speed and increasing the impeller diameter, both of which lead to a significant increase in air conditioning system noise, seriously affecting the user experience. At the same time, the conventional fan casing structure design is unreasonable, and the static pressure efficiency is low, further limiting the improvement of air volume and noise control. The single impeller structure itself has aerodynamic performance bottlenecks, which are prone to turbulence, boundary layer separation and other problems, resulting in low fan efficiency and high energy consumption, which cannot meet the current industry's demand for energy-saving, environmentally friendly and high-performance fans. Summary of the Invention

[0003] This application provides a fan and refrigeration equipment to solve at least one of the above-mentioned technical problems.

[0004] The fan in the embodiments of this application includes Hair dryer The first impeller is rotatably installed inside the air duct. The first impeller includes a first hub and a first blade disposed on the first hub. The installation angle of the first blade is W1, 25°≤W1≤42°. The second impeller is rotatably installed inside the air duct. The second impeller includes a second hub and a second blade disposed on the second hub. The installation angle of the second blade is W2, 25°≤W2≤40°, and |W1-W2|≤8°. The axial clearance B1 between the first impeller and the second impeller is 10mm~60mm.

[0005] The fan provided in this application has a double impeller structure consisting of a first impeller and a second impeller. The installation angle W1 of the first blade is limited to the range of 25° to 42°, and the installation angle W2 of the second blade is limited to the range of 25° to 40°. At the same time, the angle difference between the two blades is controlled to not exceed 8°. This allows the two impellers to achieve aerodynamic matching, which is beneficial for effectively increasing air volume without excessively increasing the rotational speed or impeller diameter. It also avoids significant noise increases caused by excessively high rotational speed or excessively large impellers. By controlling the axial clearance B1 between the first impeller and the second impeller to be between 10mm and 60mm, a reasonable transition and rectification space is provided for the interstage airflow. This helps to reduce turbulence and boundary layer separation, improve static pressure efficiency, and thus reduce operating noise while achieving large air volume output, thereby improving the overall aerodynamic performance and energy efficiency of the fan.

[0006] In some embodiments, the air inlet end of the air duct is provided with an outwardly rounded first corner flange.

[0007] Thus, by setting an outward-facing first rounded corner flange at the air inlet end of the air duct, the flange forms a collector structure, which helps to guide the airflow to be drawn in in a streamlined manner, reduces flow separation and resistance loss at the air inlet, realizes the rapid intake of a large amount of airflow, and improves the intake efficiency and effective air volume.

[0008] In some embodiments, the air outlet end of the air duct is provided with an outward-facing second rounded corner flange.

[0009] Thus, by setting an outward second rounded corner flange at the air outlet of the blower, the flange forms a diffuser structure, which helps to gradually slow down the flow velocity when the air flows out. According to Bernoulli's principle, the static pressure is restored and further increased after the fluid velocity is slowed down, thereby increasing the pressure at the blower outlet and realizing the improvement of static pressure efficiency and the reduction of exhaust loss.

[0010] In some embodiments, the radius of the rounded corner of the first rounded corner flange is 50mm to 150mm; and / or The radius of the rounded corner of the second rounded corner flange is 50mm to 150mm.

[0011] Thus, by limiting the radius of the first and second rounded corner flanges, it is beneficial to ensure the rapid intake of a large amount of airflow, minimize the vortex loss at the air inlet, thereby improving intake efficiency and flow stability. At the same time, it is beneficial to achieve the maximum recovery of static pressure while avoiding boundary layer separation, thereby effectively improving the static pressure efficiency at the fan outlet and reducing exhaust vortex noise caused by sudden changes in flow velocity.

[0012] In some embodiments, the air inlet installation angle of the first blade is W. 11 ,10°≤|W 11-W1|≤20°; and / or The outlet angle of the first blade is W. 12 ,10°≤|W 12 -W1|≤20.

[0013] In this way, by limiting the air inlet installation angle, the air outlet installation angle, and the air outlet angle of the first blade, the air inlet angle of the first blade is matched with the incoming flow direction. This helps to reduce the impact loss and separation phenomenon when the airflow enters the first impeller, thereby improving the air inlet efficiency of the first impeller. It also helps to control the flow state of the airflow at the outlet of the first impeller, reduce the turbulence and energy dissipation of the airflow before entering the second impeller, and achieve a smooth transition of the airflow between stages.

[0014] In some embodiments, the air inlet installation angle of the second blade is W. 21 ,10°≤|W 21 -W2|≤20°; and / or The outlet angle of the second blade is W. 22 ,10°≤|W 22 -W2|≤20°.

[0015] In this way, by limiting the air inlet installation angle, the air outlet installation angle, and the air outlet angle of the second blade, the air inlet angle of the second blade can be adapted to the airflow direction from the first impeller. This helps to reduce the impact and vortex loss when the airflow enters the second impeller, improves the aerodynamic efficiency of the two-stage impeller working together, and at the same time, helps to reduce the kinetic energy loss and vortex noise when the airflow is discharged, achieves smooth airflow in the fan outlet section, and improves static pressure efficiency and overall performance.

[0016] In some embodiments, the leading edge of the first blade has a forward bending angle of A1, where 20° ≤ A1 ≤ 40°, and the trailing edge of the first blade has a forward bending angle of A2, where |A1 - A2| ≤ 10°.

[0017] Thus, by limiting the leading edge bend angle of the first blade to 20° to 40° and controlling the difference between the trailing edge bend angle and the leading edge bend angle to within 10°, it is beneficial to achieve uniform pressure distribution on the blade surface while maintaining a high aerodynamic load, avoiding local flow separation and eddy shedding, thereby reducing the aerodynamic noise of the first impeller and improving its aerodynamic efficiency.

[0018] In some embodiments, the forward bend angle of the second blade is A3, 40°≤A3≤60°, and the forward bend angle of the trailing edge of the second blade is A4, |A3-A4|≤15°.

[0019] Thus, by limiting the leading edge bend angle of the second blade to 40° to 60° and controlling the difference between the trailing edge bend angle and the leading edge bend angle to within 15°, it is beneficial to enable the second blade to maintain the stability of flow adhesion under high airflow speed, reduce the vortex intensity and broadband noise in the blade wake region, and achieve efficient and low-noise operation of the second impeller under high aerodynamic load.

[0020] In some embodiments, the hub ratio of the first impeller is 2 to 3.5, and the relationship between the outer edge length L1 and the root length L2 of the first blade is 1.5 ≤ L1 / L2 ≤ 3.5; and / or The hub ratio of the second impeller 201 is 2~3.5, and the relationship between the outer edge length L3 and the root length L4 of the second blade is 1.5≤L3 / L4≤3.5.

[0021] In this way, by setting the hub ratio of the first impeller and the second impeller, and limiting the ratio of the outer edge length of the first blade to the root length of the second blade, it is beneficial to improve air volume and efficiency, avoid the decrease in energy transfer efficiency and increase in noise caused by unreasonable blade shape, and help maintain the efficient and low-noise operation of the fan in a wide range of operating conditions.

[0022] Another embodiment of the refrigeration device of this application includes the fan described in any of the above claims.

[0023] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the internal structure of the fan according to an embodiment of this application; Figure 2 This is a partial structural schematic diagram of the fan according to an embodiment of this application; Figure 3 This is a schematic diagram of the velocity streamlines of the first and second impellers according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the fan according to an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the first impeller according to an embodiment of this application; Figure 6This is a schematic diagram of the structure of the second impeller according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the first impeller and the second impeller according to an embodiment of this application.

[0025] Explanation of reference numerals in the attached drawings: Fan 100, air duct 10, air inlet 11, air outlet 12, first rounded corner flange 13, second rounded corner flange 14, first impeller 20, first hub 21, first blade 22, second impeller 30, second hub 31, second blade 32, first motor 40, second motor 50, first mounting bracket 60, second mounting bracket 70, first mounting part 80, second mounting part 90. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In the description of this application, it should be noted that, unless otherwise expressly 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 mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] This disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described herein. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0030] Please see Figure 1 and Figure 2 The refrigeration equipment of this application includes a fan 100, which includes a fan casing 10, a first impeller 20, and a second impeller 30. The first impeller 20 is rotatably installed inside the fan casing 10 and includes a first hub 21 and a first blade 22 disposed on the first hub 21. The installation angle of the first blade 22 is W1, 25°≤W1≤42°. The second impeller 30 is rotatably installed inside the fan casing 10 and includes a second hub 31 and a second blade 32 disposed on the second hub 31. The installation angle of the second blade 32 is W2, 25°≤W2≤40°, and |W1-W2|≤8°. The axial clearance B1 between the first impeller 20 and the second impeller 30 is 10mm~60mm.

[0031] The fan 100 provided in this application forms a double impeller structure by setting a first impeller 20 and a second impeller 30. The installation angle W1 of the first blade is limited to the range of 25° to 42°, and the installation angle W2 of the second blade is limited to the range of 25° to 40°. At the same time, the angle difference between the two blades is controlled to not exceed 8°, so that the two impellers are synergistically matched in terms of aerodynamic performance. This is beneficial to effectively increase the air volume without excessively increasing the speed or the impeller diameter, and avoids the significant increase in noise caused by excessive speed or excessive impeller size. By controlling the axial clearance B1 between the first impeller 20 and the second impeller 30 to be between 10mm and 60mm, a reasonable transition and rectification space is provided for the interstage airflow, which helps to reduce turbulence and boundary layer separation, and improve static pressure efficiency. Thus, while achieving a large air volume output, the operating noise is reduced, and the overall aerodynamic performance and energy efficiency of the fan 100 are improved.

[0032] Refrigeration equipment refers to a device that transfers heat through a refrigeration cycle, mainly used to lower the temperature and maintain a low-temperature environment. In the embodiments of this application, the refrigeration equipment may be a heat pump or an air conditioner.

[0033] In the embodiments of this application, the fan 100 of this application adopts a two-stage impeller series structure. The core components include the fan casing 10, the first impeller 20 and the second impeller 30. The fan casing 10 serves as the load-bearing foundation and airflow channel of the entire fan 100. It can be integrally formed using materials such as aluminum alloy, which ensures structural rigidity and effectively reduces the noise generated by its own vibration.

[0034] Furthermore, the inner diameter of the duct 10 is designed to be adapted to the size of the two-stage impellers to ensure that there is a reasonable gap between the impeller and the inner wall of the duct 10 when the impeller rotates. The gap is controlled at 5-8mm, which avoids frictional interference between the impeller and the duct 10 when the impeller rotates and reduces energy loss caused by airflow leakage from the gap.

[0035] In this embodiment, both the first impeller 20 and the second impeller 30 are rotatably mounted inside the air duct 10 and arranged sequentially along the axial direction of the air duct 10. Their central axes coincide with the central axis of the air duct 10, ensuring smooth airflow along the axial direction of the air duct 10 and avoiding airflow turbulence caused by axial misalignment. During the operation of the fan 100, the first impeller 20 rotates clockwise, and the second impeller 30 rotates counterclockwise; their rotation directions are opposite.

[0036] In this embodiment, the first impeller 20 includes a first hub 21 and first blades 22 uniformly disposed on the outer periphery of the first hub 21. The first hub 21 adopts a stepped structure and is fixed to the drive component by key connection to ensure the stability of power transmission. In some embodiments, the first blades 22 and the first hub 21 can be fixed by welding. The weld is polished smooth to reduce the resistance when the airflow passes through. The number of first blades 22 is set to 4 to 8, which are evenly distributed on the first hub 21. The included angle between two adjacent first blades 22 is equal to ensure that the blades are subjected to uniform force and that the airflow can enter the impeller evenly.

[0037] The blade installation angle refers to the tilt angle of the blade relative to the hub or impeller rotation plane, and is a key aerodynamic parameter in the design of the fan 100. In the embodiment of this application, the installation angle of the first blade 22 is W1, and is strictly controlled within 25°≤W1≤42°. This installation angle range enables the first blade 22 to obtain the best airflow capture efficiency when rotating.

[0038] The second impeller 30 has a similar structure to the first impeller 20, including a second hub 31 and second blades 32 disposed on the outer periphery of the second hub 31. The structure of the second hub 31 is adapted to the first hub 21. In some embodiments, the number of second blades 32 is also set to 3 to 6, usually fewer than the number of first blades 22. Specifically, in the embodiments of this application, the number of first blades 22 is 5, and the number of second blades 32 is 3. In this embodiment, the installation angle of the second blade 32 is W2, also limited to 25°≤W2≤40°, and the absolute value of the difference between the two installation angles, |W1-W2|≤8°. Simultaneously, the axial clearance B1 between the second impeller 30 and the first impeller 20 is 10mm~60mm, ensuring optimal matching of the airflow inlet and outlet angles between the two impeller stages. This effectively avoids impacts, eddies, and boundary layer separation during interstage transitions, thereby significantly reducing aerodynamic noise during the operation of the fan 100. Figure 3 As shown, the streamlines of the airflow in the first impeller 20 and the second impeller 30 are relatively smooth, with no boundary layer separation, no separation vortex or shedding vortex generated, and good aerodynamic performance. This indicates that the installation angle fit and axial spacing of the first impeller 20 and the second impeller 30 have reached the optimal values, and the aerodynamic performance and noise performance of the fan 100 are the best at this time.

[0039] Please see Figure 3Furthermore, the height of the first impeller 20 is B2, and the height of the second impeller 30 is B3. When B3 / B2 < 0.8, the second impeller 30 is too small and may limit the airflow capacity; when B3 / B2 > 1.4, the second impeller 30 is too large and may increase the airflow resistance. Both of these will affect the efficiency and noise performance of the fan 100. Therefore, in this embodiment, the relationship between the height B2 of the first impeller 20 and the height B3 of the second impeller 30 is 0.8 ≤ B3 / B2 ≤ 1.4.

[0040] Please see Figure 1 In this embodiment of the application, the fan 100 further includes a first motor 40, a second motor 50, a first mounting bracket 60, and a second mounting bracket 70. The first mounting bracket 60 and the second mounting bracket 70 are respectively installed at both ends of the fan duct 10. The first motor 40 is installed on the fan duct 10 through the first mounting bracket 60, the second motor 50 is installed on the fan duct 10 through the second mounting bracket 70, the first impeller 20 is installed on the output shaft of the first motor 40, and the second impeller 30 is installed on the output shaft of the second motor 50.

[0041] Specifically, in this embodiment, the first mounting bracket 60 and the second mounting bracket 70 are respectively fixedly installed at both ends of the air duct 10, arranged symmetrically and perpendicular to the axis of the air duct 10, ensuring that the axes of the motor and impeller coincide with the axis of the air duct 10 after installation. The first mounting bracket 60 adopts a frame structure, which is welded from crossbeams and longitudinal beams. The size of the frame is adapted to the size of the end of the air duct 10. The edge of the mounting bracket is provided with mounting holes, and it is fixedly connected to the flange at the end of the air duct 10 by bolts, ensuring the firmness of the connection and preventing the connection from loosening due to vibration during the operation of the fan 100.

[0042] In this embodiment, the first motor 40 is fixedly mounted on the air duct 10 by the first mounting bracket 60. In some embodiments, a shock-absorbing pad is provided between the housing of the first motor 40 and the first mounting bracket 60, which can effectively absorb the vibration generated during the operation of the motor, reduce the vibration transmitted to the air duct 10 and the impeller, and thus reduce the overall noise.

[0043] In some embodiments, the output shaft of the first motor 40 is fixedly connected to the first hub 21 of the first impeller 20. The connection method can be a key connection with a set screw locking, which not only ensures the reliability of power transmission, but also facilitates subsequent disassembly and maintenance.

[0044] In some embodiments, the structure of the second mounting bracket 70 is completely identical to that of the first mounting bracket 60, ensuring the symmetry and consistency of the installation. The second motor 50 is mounted on the other end of the air duct 10 through the second mounting bracket 70. Shock-absorbing pads are also provided between the second motor 50 and the second mounting bracket 70, and its installation method is the same as that of the first motor 40.

[0045] The second impeller 30 is mounted on the output shaft of the second motor 50 and is arranged corresponding to the first impeller 20 along the axis of the wind tunnel 10. In some embodiments, the distance between the second impeller 30 and the first impeller 20 is reasonably set according to the length of the wind tunnel 10 and the size of the impeller. It is usually controlled at 1 / 2 of the length of the wind tunnel 10 to ensure that the airflow has enough space to smoothly transition after being accelerated by the first impeller 20 before entering the second impeller 30 for secondary acceleration. This avoids mutual interference of airflow due to the two impellers being too close together, or loss of airflow energy due to the distance being too far.

[0046] Please see Figure 1 and Figure 4 In some embodiments, the air inlet end 11 of the air duct 10 is provided with an outwardly rounded corner flange 13.

[0047] Thus, by setting an outward-facing first rounded corner flange 13 at the air inlet end 11 of the air duct 10, the flange forms a collector structure, which helps to guide the airflow to be concentrated and drawn in in a streamlined manner, reduces the flow separation and resistance loss at the air inlet, realizes the rapid intake of a large amount of airflow, and improves the intake efficiency and effective air volume.

[0048] In some embodiments, the air inlet end 11 of the air duct 10 is provided with an outward first rounded corner flange 13. The first rounded corner flange 13 adopts a structure integrally formed with the air duct 10, and the material is consistent with the air duct 10, so as to avoid structural weakness and airflow leakage caused by splicing connection. The extension direction of the flange is inclined outward and forms a certain angle with the axis of the air duct 10, so as to ensure that the airflow can be better guided into the air duct 10.

[0049] In this embodiment, the end of the duct 10 near the first impeller 20 is the air inlet end 11. The fan 100 also includes a first mounting part 80, which is mounted on the air inlet end 11 of the duct 10. The first rounded corner flange 13 is provided at the connection between the first mounting part 80 and the duct 10 and forms a transition between the first mounting part 80 and the duct 10.

[0050] In this embodiment, the first mounting part 80 serves as the mounting structure between the fan 100 and the refrigeration equipment, and is fixedly installed at the air inlet end 11 of the air duct 10. The first mounting part 80 adopts a ring structure, with its inner diameter being consistent with the inner diameter of the air duct 10, and its outer diameter being adapted to the size of its installation position in the refrigeration equipment.

[0051] In this embodiment, the first rounded corner flange 13 is disposed at the connection between the first mounting part 80 and the air duct 10, specifically between the inner periphery of the first mounting part 80 and the outer edge of the air inlet end 11 of the air duct 10, forming a smooth transition between the first mounting part 80 and the air duct 10. The inner side of the flange is flush with the inner wall of the air duct 10 and the inner wall of the first mounting part 80 to avoid forming a stepped structure and prevent eddies and resistance from being generated when the airflow passes through.

[0052] Please see Figure 1 and Figure 4 In some embodiments, the air outlet 12 of the air duct 10 is provided with an outwardly rounded corner flange 14.

[0053] Thus, by setting an outward second rounded corner flange 14 at the air outlet 12 of the air duct 10, the flange forms a diffuser structure, which helps to gradually slow down the flow velocity when the air flows out. According to Bernoulli's principle, after the fluid velocity slows down, the static pressure is restored and further increased, thereby increasing the pressure at the outlet of the fan 100, achieving an improvement in static pressure efficiency and a reduction in exhaust loss.

[0054] Specifically, in this embodiment, the air outlet 12 of the air duct 10 is provided with an outward second rounded corner flange 14, which corresponds to the first rounded corner flange 13 of the air inlet 11. The second rounded corner flange 14 is a key component of the air outlet structure of the air duct 10. Its structural design and position arrangement directly affect the exhaust efficiency and static pressure recovery effect of the fan 100, and it works in coordination with the air duct 10 and the second mounting part 90.

[0055] In this embodiment, the second rounded corner flange 14 also adopts a structure integrally formed with the air duct 10, and the material is consistent with the air duct 10 and the first rounded corner flange 13 to ensure the integrity and stability of the structure. The extension direction of the flange is outward and the included angle with the first rounded corner flange 13 is consistent, making the overall structure of the fan 100 more symmetrical, and at the same time facilitating the smooth discharge of airflow.

[0056] In this embodiment, the end of the duct 10 near the second impeller 30 is the air outlet 12. The fan 100 also includes a second mounting part 90, which is mounted on the air outlet 12 of the duct 10. The second rounded flange 14 is provided at the connection between the second mounting part 90 and the duct 10 and forms a transition between the second mounting part 90 and the duct 10.

[0057] In this embodiment, the second mounting part 90 has the same structure as the first mounting part 80, both being annular structures, and is fixedly installed at the air outlet 12 of the air duct 10. The inner diameter of the second mounting part 90 is consistent with the outer diameter of the air duct 10, and the outer diameter is adapted to the size of its installation position in the refrigeration equipment.

[0058] In this embodiment, the second rounded corner flange 14 is disposed at the connection between the second mounting part 90 and the air duct 10, specifically between the outer periphery of the second mounting part 90 and the outer edge of the air outlet 12 of the air duct 10, forming a smooth transition between the second mounting part 90 and the air duct 10. The inner side of the flange is flush with the inner wall of the air duct 10 and the inner wall of the second mounting part 90, avoiding the formation of a stepped structure, preventing vortices and resistance when the airflow is discharged, and ensuring that the airflow can be discharged smoothly.

[0059] Please see Figure 1 and Figure 4 In some embodiments, the radius of the rounded corner of the first rounded corner flange 13 is 50mm to 150mm; and / or, the radius of the rounded corner of the second rounded corner flange 14 is 50mm to 150mm.

[0060] Thus, by limiting the radius of the first rounded flange 13, the wall pressure gradient can be made gentler during the accelerated intake process, avoiding airflow separation due to excessive curvature or increased intake resistance due to excessive curvature. This helps to minimize vortex losses at the intake while ensuring rapid intake of a large amount of airflow, thereby improving intake efficiency and flow stability. At the same time, limiting the radius of the second rounded flange 14 can further optimize the shape of the diffuser's expansion channel, making the airflow velocity decrease uniformly during deceleration and diffusion. This helps to achieve maximum static pressure recovery while avoiding boundary layer separation, thereby effectively improving the static pressure efficiency at the outlet of the fan 100 and reducing exhaust vortex noise caused by sudden changes in flow velocity.

[0061] In some embodiments, the range of fillet radius values ​​is typically determined based on aerodynamic simulation and actual testing. This ensures both smooth airflow and structural strength and fabrication feasibility. Different radius values ​​can be adapted to different sizes and specifications of the duct 10, ensuring optimal aerodynamic performance under various operating conditions.

[0062] In actual processing, the fillet radius can be flexibly selected according to the inner diameter of the air duct 10. For example, when the inner diameter of the air duct 10 is small, a fillet radius of 50-80mm can be selected; when the inner diameter of the air duct 10 is large, a fillet radius of 100-150mm can be selected to ensure that the flange structure is compatible with the size of the air duct 10 and to ensure the stability of aerodynamic performance. The material is still the same high-strength aluminum alloy as the air duct 10 to ensure the structural strength of the flange and avoid deformation caused by airflow impact during long-term use.

[0063] Please see Figure 2 In some embodiments, the air inlet installation angle of the first blade 22 is W. 11 ,10°≤|W 11 -W1|≤20°; and / or, the outlet installation angle of the first blade 22 is W 12,10°≤|W 12 -W1|≤20.

[0064] Thus, by limiting the absolute value of the difference between the inlet installation angle and the first blade 22 installation angle to 10° to 20°, the inlet angle of the first blade 22 is matched with the incoming flow direction, which helps to reduce the impact loss and separation phenomenon when the airflow enters the first impeller 20, thereby improving the intake efficiency of the first impeller 20. Furthermore, by limiting the absolute value of the difference between the outlet installation angle and the first blade 22 installation angle to 10° to 20°, the outlet angle of the first blade 22 is matched with the interstage airflow transition requirements, which helps to control the flow state of the airflow at the outlet of the first impeller 20, reduce the turbulence and energy dissipation of the airflow before entering the second impeller 30, and achieve a smooth transition of the interstage airflow.

[0065] Specifically, the inlet and outlet installation angles of the first blade 22 are important parameters in the structural design of the first blade 22. The inlet installation angle refers to the installation angle at the leading edge of the blade, and the outlet installation angle refers to the installation angle at the trailing edge of the blade.

[0066] In the embodiments of this application, 10°≤|W 11 -W1|≤20°, and at the same time, 10°≤|W 12 -W1|≤20°. For example, when W1 is 25°, W 11 The angle can be selected within the range of 5°~15° or 35°~45° to ensure that the absolute value of the difference meets the requirements and adapts to the actual airflow direction. Furthermore, when W1 is 35°, W... 12 It can be selected within the range of 15°~25° or 45°~55° to ensure that it is adapted to the interstage airflow transition requirements.

[0067] In some embodiments, the design of the air inlet and air outlet installation angles of the first blade 22 also needs to be coordinated with the number and shape of the first blade 22 to ensure smooth airflow between adjacent blades, avoid airflow interference between blades, further improve the aerodynamic efficiency and quiet performance of the first impeller 20, and the material is consistent with the first blade 22 to ensure the integrity and stability of the structure.

[0068] Please see Figure 2 In some embodiments, the air inlet installation angle of the second blade 32 is W. 21 ,10°≤|W 21 -W2|≤20°; and / or, the outlet installation angle of the second blade 32 is W 22 ,10°≤|W 22 -W2|≤20°.

[0069] Thus, by limiting the absolute value of the difference between the inlet installation angle and the installation angle of the second blade 32 to 10° to 20°, the inlet angle of the second blade 32 can adapt to the airflow direction from the first impeller 20. This helps to reduce the impact and vortex loss when the airflow enters the second impeller 30, and improves the aerodynamic efficiency of the two-stage impeller working together. At the same time, by limiting the absolute value of the difference between the outlet installation angle and the installation angle of the second blade 32 to 10° to 20°, the outlet angle of the second blade 32 matches the airflow diffusion direction at the outlet of the duct 10. This helps to reduce the kinetic energy loss and vortex noise when the airflow is discharged, and achieves smooth airflow in the outlet section of the fan 100, improving static pressure efficiency and overall performance.

[0070] Specifically, in some embodiments, 10° ≤ |W 21 -W2|≤20°, and at the same time, 10°≤|W 22 -W2|≤20°. For example, when W2 is 30°, W 21 The angle can be selected within the range of 10°~20° or 40°~50° to ensure that the absolute value of the difference meets the requirements, while adapting to the airflow direction discharged from the first impeller 20. Furthermore, when W2 is 28°, W... 22 The angle can be selected within the range of 8°~18° or 38°~48° to ensure that it matches the airflow diffusion direction of the air outlet of the air duct 10.

[0071] In some embodiments, the design of the inlet and outlet installation angles of the second blade 32 also needs to be coordinated with the number and shape of the second blade 32 and the outlet angle of the first blade 22 to ensure smooth airflow transition between the two impellers, avoid airflow turbulence, and further improve the overall operating efficiency and noise reduction of the fan 100.

[0072] Please see Figure 5 In some embodiments, the leading edge of the first blade 22 has a forward bending angle of A1, where 20° ≤ A1 ≤ 40°, and the trailing edge of the first blade 22 has a forward bending angle of A2, where |A1-A2| ≤ 10°.

[0073] Thus, by limiting the leading edge bending angle of the first blade 22 to 20° to 40° and controlling the difference between the trailing edge bending angle and the leading edge bending angle to within 10°, it is beneficial to achieve uniform pressure distribution on the blade surface while maintaining a high aerodynamic load, avoiding local flow separation and eddy shedding, thereby reducing aerodynamic noise and improving aerodynamic efficiency of the first impeller 20.

[0074] Specifically, the leading edge bend angle and the trailing edge bend angle are also key parameters for blade aerodynamic design. The leading edge bend angle refers to the bend angle of the leading edge of the blade relative to the blade baseline, while the trailing edge bend angle refers to the degree of bend of the trailing edge of the blade relative to the baseline.

[0075] When the leading edge curvature angle A1 of the first blade 22 is less than 20°, the blade's leading edge curvature is insufficient, resulting in low airflow capture efficiency and difficulty in meeting the airflow requirements of the fan 100. When A1 is greater than 40°, the blade's leading edge curvature is too large, leading to uneven pressure distribution on the blade surface, which easily causes local flow separation, increases eddy noise, and reduces aerodynamic efficiency. Therefore, in this embodiment, the leading edge curvature angle A1 of the first blade 22 is limited to the range of 20° to 40°.

[0076] Furthermore, the difference between the trailing edge curvature angle A2 and the leading edge curvature angle A1 of the first blade 22 is controlled within 10°, i.e., |A1-A2|≤10°. For example, when A1 is 25°, A2 can be selected within the range of 15° to 35°; when A1 is 35°, A2 can be selected within the range of 25° to 45°, ensuring that the difference meets the requirements.

[0077] In some embodiments, the leading and trailing edges of the first blade 22 are rounded with a radius of 2 to 5 mm to reduce airflow resistance. The blade thickness gradually decreases from the root to the tip to ensure a balance between the blade's structural strength and aerodynamic performance.

[0078] Please see Figure 6 In some embodiments, the forward bend angle of the second blade 32 is A3, 40°≤A3≤60°, and the forward bend angle of the trailing edge of the second blade 32 is A4, |A3-A4|≤15°.

[0079] Thus, by limiting the leading edge bending angle of the second blade 32 to 40° to 60° and controlling the difference between the trailing edge bending angle and the leading edge bending angle to within 15°, it is beneficial for the second blade 32 to maintain the stability of flow adhesion under high airflow speed, reduce the vortex intensity and broadband noise in the blade wake region, and achieve efficient and low-noise operation of the second impeller 30 under high aerodynamic load.

[0080] Specifically, in some embodiments, when A3 is less than 40°, the leading edge of the blade is not sufficiently curved, making it difficult to adapt to the impact of high-speed airflow, easily causing airflow separation and reducing aerodynamic efficiency; when A3 is greater than 60°, the leading edge of the blade is too curved, resulting in an excessive pressure gradient on the blade surface, generating severe eddies and noise, affecting the quiet performance of the fan 100. Therefore, the leading edge curvature angle A3 of the second blade 32 is limited to the range of 40° to 60°.

[0081] Furthermore, the difference between the trailing edge bend angle A4 and the leading edge bend angle A3 of the second blade 32 is controlled within 15°, i.e., |A3-A4|≤15°. For example, when A3 is 45°, A4 can be selected within the range of 30° to 60°; when A3 is 55°, A4 can be selected within the range of 40° to 70°, ensuring that the difference meets the requirements.

[0082] In some embodiments, the leading and trailing edges of the second blade 32 are also rounded with a radius of 3 to 6 mm to adapt to the impact of high-speed airflow and reduce drag loss.

[0083] Please see Figure 7 In some embodiments, the hub ratio of the first impeller 20 is 2 to 3.5, and the relationship between the outer edge length L1 and the root length L2 of the first blade 22 is 1.5 ≤ L1 / L2 ≤ 3.5; and / or, the hub ratio of the second impeller 30201 is 2 to 3.5, and the relationship between the outer edge length L3 and the root length L4 of the second blade 32 is 1.5 ≤ L3 / L4 ≤ 3.5.

[0084] Thus, by limiting the hub ratio of the first impeller 20 and the second impeller 30 to 2 to 3.5, and limiting the ratio of the outer edge length of the first blade 22 and the blade root length of the second blade 32 to 1.5 to 3.5, it is beneficial to rationally distribute the load distribution along the blade span, avoiding flow separation at the blade root due to an excessively small hub ratio or insufficient airflow due to an excessively large hub ratio. This achieves a coordinated unity between the aerodynamic performance and structural strength of the first impeller 20, which is beneficial to improving airflow and efficiency. At the same time, it avoids the decrease in energy transfer efficiency and the increase in noise due to unreasonable blade shape, and achieves aerodynamic matching between the second impeller 30 and the first impeller 20. This is beneficial to maintaining the efficient and low-noise operation of the fan 100 within a wide operating range.

[0085] Specifically, in this embodiment, the hub ratio refers to the ratio of the diameter of the impeller hub to the outer diameter of the blade. The diameter of the first hub 21 is D1, the outer diameter of the first blade 22 is D2, the diameter of the second hub 31 is D3, and the outer diameter of the second blade 22 is D4. The hub ratios of the first impeller 20 and the second impeller 30 are both limited to the range of 2 to 3.5, that is, 2≤D2 / D1≤3.5 and 2≤D4 / D3≤3.5. This is beneficial for the reasonable distribution of load along the blade span, avoiding airflow separation at the blade root due to a hub ratio that is too small (i.e., less than 2), preventing vortices from forming at the blade root, and reducing energy loss and noise. At the same time, it also avoids the reduction of the effective working area of ​​the blade due to a hub ratio that is too large (i.e., greater than 3.5), which would result in insufficient airflow and fail to meet the actual usage requirements of the fan 100.

[0086] In this embodiment, the outer edge length L1 of the first blade 22 refers to the distance from the outermost end of the blade to the center of the hub, and the blade root length L2 refers to the distance from the connection between the blade and the hub to the center of the hub. The ratio of the two is controlled within the range of 1.5 to 3.5. This design can optimize the spanwise shape of the first blade 22, make the load distribution of the blade more uniform, and avoid the decrease in energy transfer efficiency and increase in noise caused by unreasonable blade shape.

[0087] For example, when L2 is 100mm, L1 can be selected within the range of 150 to 350mm to ensure that the ratio meets the requirements and is compatible with the hub ratio and overall size of the first impeller 20.

[0088] In this embodiment, the hub ratio of the second impeller 30 is consistent with that of the first impeller 20, both being 2 to 3.5, to ensure aerodynamic matching between the two impeller stages. The ratio of the outer edge length L3 to the root length L4 of the second blade 32 is also controlled within the range of 1.5 to 3.5, consistent with the ratio range of the first blade 22, to ensure that the shape of the second blade 32 is adapted to the first blade 22, thereby achieving a smooth airflow transition between the two impeller stages. This is beneficial for maintaining the efficient and low-noise operation of the fan 100 within a wide operating range.

[0089] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.

[0091] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A fan, characterized in that, include Hair dryer The first impeller is rotatably installed inside the air duct. The first impeller includes a first hub and a first blade disposed on the first hub. The installation angle of the first blade is W1, 25°≤W1≤42°. The second impeller is rotatably installed inside the air duct. The second impeller includes a second hub and a second blade disposed on the second hub. The installation angle of the second blade is W2, 25°≤W2≤40°, and |W1-W2|≤8°. The axial clearance B1 between the first impeller and the second impeller is 10mm~60mm.

2. The fan according to claim 1, characterized in that, The air inlet end of the air duct is provided with an outward-facing first rounded corner flange.

3. The fan according to claim 2, characterized in that, The air outlet end of the air duct is provided with an outward-facing second rounded corner flange.

4. The fan according to claim 3, characterized in that, The radius of the rounded corner of the first rounded corner flange is 50mm to 150mm; and / or The radius of the rounded corner of the second rounded corner flange is 50mm to 150mm.

5. The fan according to claim 1, characterized in that, The air inlet installation angle of the first blade is W. 11 ,10°≤|W 11 -W1|≤20°; and / or The outlet angle of the first blade is W. 12 ,10°≤|W 12 -W1|≤20.

6. The fan according to claim 1, characterized in that, The air inlet installation angle of the second blade is W. 21 ,10°≤|W 21 -W2|≤20°; and / or The outlet angle of the second blade is W. 22 ,10°≤|W 22 -W2|≤20°.

7. The fan according to claim 1, characterized in that, The leading edge of the first blade has a forward bending angle of A1, where 20° ≤ A1 ≤ 40°, and the trailing edge of the first blade has a forward bending angle of A2, where |A1 - A2| ≤ 10°.

8. The fan according to claim 1, characterized in that, The forward bend angle of the second blade is A3, 40°≤A3≤60°, and the forward bend angle of the trailing edge of the second blade is A4, |A3-A4|≤15°.

9. The fan according to claim 1, characterized in that, The hub ratio of the first impeller is 2~3.5, and the relationship between the outer edge length L1 and the root length L2 of the first blade is 1.5≤L1 / L2≤3.5; and / or The hub ratio of the second impeller is 2 to 3.5, and the relationship between the outer edge length L3 and the root length L4 of the second blade is 1.5 ≤ L3 / L4 ≤ 3.

5.

10. A refrigeration device, characterized in that, Includes the wind turbine as described in any one of claims 1-9.

Images