Wind wheel assembly, fan and range hood

Abstract

The embodiment of the invention provides a wind wheel assembly, a fan and a range hood, and relates to the technical field of kitchenware, the wind wheel assembly is provided with a first wind wheel and a second wind wheel, the first wind wheel comprises a first frame body and a plurality of first blades, the second wind wheel comprises a second frame body and a plurality of second blades, and the second wind wheel is located in an air inlet space formed by the first blades; therefore, the airflow is primarily pressurized and accelerated when passing through the second blade, and then is pressurized and accelerated again when passing through the first blade, so that the static pressure of the wind wheel assembly can be increased, and the problem that a low-floor range hood is large in pipe network resistance and difficult to exhaust smoke is solved.

Description

Technical Field

[0001] This application relates to the field of kitchenware technology, and in particular to a fan assembly, a fan, and a range hood. Background Technology

[0002] The two most important performance indicators for range hoods are air volume and static pressure. Range hoods with high air volume have better smoke extraction effects and can quickly draw in cooking fumes; range hoods with high static pressure can overcome higher pipe network resistance, allowing them to maintain a large air volume even under high back pressure conditions.

[0003] In related technologies, to increase the air volume of a range hood, the inner and outer diameters of a single-sided air intake impeller can be increased, which leads to an increase in impeller weight and motor power; or a fan system with a double-sided air intake impeller can be used, which can make full use of the area on the motor side of the fan system to improve the airflow inside the range hood and increase the air volume; or a dual-fan range hood can be used, whose dual air intakes can be directly aimed at the stove, hoping to achieve the goal of large air volume and good oil fume extraction effect.

[0004] Although the above measures increased the air intake volume, the static pressure did not improve significantly, and it was still difficult to solve the problem of high pipe network resistance and difficulty in smoke exhaust in low-rise buildings. Summary of the Invention

[0005] This application provides a fan assembly, a fan, and a range hood, which can improve the exhaust static pressure of the fan assembly by setting a first fan and a second fan, thereby improving the problem of high pipe network resistance and difficulty in smoke exhaust in high-rise range hoods.

[0006] This application provides a wind turbine assembly, including:

[0007] The first wind turbine includes a first frame and a plurality of first blades, the plurality of first blades being circumferentially spaced along the first frame to form an air intake space; and

[0008] The second impeller is located within the air intake space and is spaced apart from the first impeller. The axis of the first impeller is parallel to the axis of the second impeller. The second impeller includes a second frame and a plurality of second blades, which are distributed circumferentially along the second frame.

[0009] Furthermore, the rotation direction of the first blade is opposite to that of the second blade.

[0010] Furthermore, the number of the first blades is n1, and the number of the second blades is n2;

[0011] Where n1 satisfies: 40≤n1≤70, n2 satisfies: 10≤n2≤60, and n2<n1;

[0012] And / or, n1 and n2 are coprime numbers.

[0013] Furthermore, the axis of the first wind turbine coincides with the axis of the second wind turbine.

[0014] Furthermore, each of the first blades has a leading edge surface facing the air intake space and a trailing edge surface facing away from the air intake space, and both ends of the leading edge surface have guide arc surfaces, which are concave towards the trailing edge surface.

[0015] Furthermore, the guide arc surface at one end of the leading edge is a first guide arc surface, and the guide arc surface at the other end of the leading edge is a second guide arc surface. The first guide arc surface extends from the leading edge to the first end face of the first blade, and the second guide arc surface extends from the leading edge to the second end face of the first blade.

[0016] Furthermore, the orthographic projections of the leading edge surface and the trailing edge surface onto the plane passing through the second end face have corresponding leading edge lines and trailing edge lines. The line connecting the end of the leading edge line facing the air intake space and the end of the second leading edge line facing the air intake space is parallel to the reference plane. The reference plane is perpendicular to the second end face. The distance between the projections of the end of the leading edge line facing away from the air intake space and the end of the trailing edge line facing away from the air intake space onto the reference plane along the extension direction of the connecting line is W1.

[0017] The distance between the projections of the two ends of the first guide arc surface onto the reference plane along the extension direction of the connecting line is W2, wherein W2 satisfies 0.1W1≤W2≤0.5W1;

[0018] And / or, the distance between the projections of the two ends of the second guide arc surface onto the reference plane along the extension direction of the connecting line is W3, wherein W3 satisfies 0.1W1≤W3≤0.5W1;

[0019] And / or, the first blade has a first guiding arc corresponding to the first guiding arc surface in the vertical projection, the length of the first guiding arc being R1, and the first blade has a second guiding arc corresponding to the second guiding arc surface in the vertical projection, the length of the second guiding arc being R2, wherein R1≤R2.

[0020] Furthermore, at least one of the trailing edge surface and the leading edge surface of the first blade is provided with a first flow guiding structure, the first flow guiding structure extending along the axial direction of the first impeller.

[0021] A second aspect of this application provides a wind turbine, comprising:

[0022] The wind turbine assembly described above; and

[0023] A range hood volute, the range hood volute comprising a housing, the housing forming a wind cavity and an air inlet and an air outlet communicating with the wind cavity;

[0024] The wind turbine assembly is located inside the wind cavity.

[0025] Further, the housing includes:

[0026] First end plate;

[0027] The second end plate is disposed at a distance from the first end plate;

[0028] A peripheral side plate is located between the first end plate and the second end plate, and an air inlet communicating with the air cavity is provided on the first end plate and / or the second end plate;

[0029] The outer contour of the peripheral side plate projected onto the first plane includes a first arc, a clearance line, and a second arc arranged sequentially and connected along the periphery of the peripheral side plate. The first plane is perpendicular to the axis of the air inlet, and the radius of curvature at each point on the clearance line is greater than the radius of curvature at each point on the first arc and the second arc.

[0030] Furthermore, the maximum length of the first end plate and the second end plate along the first direction is H, and the maximum length of the first end plate and the second end plate along the second direction is W, where H < 600 mm and W < 600 mm.

[0031] Wherein, the first direction is parallel to the axial direction of the air outlet, the second direction is perpendicular to the first direction, and the second direction is parallel to the first plane.

[0032] Furthermore, the orthographic projection of the centerline of the air inlet onto the first plane is point O. The first plane has a first axis, a first reference point, and a second reference point. The first axis is parallel to the second direction and intersects with point O. The first reference point and the second reference point are symmetrically distributed about the first axis, and the distance between the first reference point and the second reference point is d, where 0.25H≤d≤0.5H.

[0033] The first axis and the avoidance line have a first intersection point. In the second direction, the shortest distance from the first intersection point to the straight line passing through the first reference point and the second reference point is a, where 0.2W≤a≤0.5W.

[0034] The distance between the flow point on the avoidance line and the first reference point is r1, and the distance between the flow point and the second reference point is r2, (0.25d). 2 ≤r1*r2≤(0.36d)2 .

[0035] Furthermore, the housing also includes an arc-shaped transition portion, one end of the peripheral side plate is connected to the first end plate through the arc-shaped transition portion, and the other end of the peripheral side plate is connected to the second end plate through the arc-shaped transition portion;

[0036] Alternatively, the peripheral side plate is connected to and perpendicular to the first end plate and the second end plate.

[0037] A third aspect of this application provides a range hood, comprising:

[0038] The main body has an air extraction port, and the main body contains a flue connected to the air extraction port; and

[0039] The aforementioned fan is located inside the main body and draws flue gas into the flue from the exhaust port.

[0040] The impeller assembly, fan, and range hood provided in this application embodiment, by setting a first impeller and a second impeller, wherein the first impeller includes a first frame and multiple first blades, and the second impeller includes a second frame and multiple second blades, wherein the second impeller is located in the air intake space formed by the multiple first blades, so that the airflow is initially pressurized and accelerated when passing through the second blades, and then pressurized and accelerated again when passing through the first blades, thereby increasing the static pressure of the wind speed assembly, and thus improving the problem of high pipe network resistance and difficulty in smoke exhaust in low-rise range hoods. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0042] Figure 1 This is a schematic diagram of the structure of a range hood in one embodiment of this application.

[0043] Figure 2 This is a schematic diagram of the structure of a fan in one embodiment of this application;

[0044] Figure 3 This is a schematic diagram of the wind turbine assembly in one embodiment of this application;

[0045] Figure 4 This is a schematic diagram of the structure of the first blade in one embodiment of this application and a projection view of the first blade on a reference plane;

[0046] Figure 5This is a projected view of the first blade on its first end face in one embodiment of this application;

[0047] Figure 6 This is a first-view structural diagram of the volute casing of a smoke machine in one embodiment of this application;

[0048] Figure 7 This is a second-view structural diagram of the flue casing in one embodiment of this application;

[0049] Figure 8 This is a schematic cross-sectional view of the volute casing of a smoke machine in one embodiment of this application;

[0050] Figure 9 This is a third-view structural diagram of the volute casing of a smoke machine in one embodiment of this application;

[0051] Figure 10 This is a schematic projection of the flue casing of the smoke machine onto a first plane in one embodiment of this application;

[0052] Figure 11 For Cassini's oval line;

[0053] Figure 12 This table presents a comparison curve of the static pressure at the air outlet of the range hood in this application with that of range hoods in related technologies. Attached image description:

[0055] 100. Range hood volute; 10. Housing;

[0056] 101. First end plate;

[0057] 102. Second end plate;

[0058] 103. Peripheral side plate; 1031. First arc surface; 103a. First arc line; 1032. Clearance surface; 103b. Clearance line; 1033. Second arc surface; 103c. Second arc line;

[0059] 105. Air inlet;

[0060] 106. Air vent;

[0061] 107. Wind cavity;

[0062] 24. Flow guide ring; 25. Second flow guide structure; 12. Limiting bracket;

[0063] 1000, Wind turbine; 200, Wind turbine assembly; 20, First wind turbine; 201, First frame; 2011, Air intake space; 202, First blade; 202a2, Guide arc surface; 2021, Leading edge surface; 2021a, Leading edge line; 2022, Trailing edge surface; 2022a, Trailing edge line; 2023, First end face; 2024, Second end face; 203, First guide structure; 21, Second wind turbine; 211, Second frame; 212, Second blade;

[0064] 2000, Range hood; 300, Main body; 301, Exhaust port; 11, Mounting bracket; 13, Check valve; 14, Top plate;

[0065] XX, first direction; YY, second direction; M, first axis. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0067] As people's living standards improve, the demand for protection from cooking fumes is also increasing, making range hoods an indispensable household appliance for purifying the kitchen environment. A range hood draws the mixture of cooking fumes and water vapor into a fan and then uses the air pressure generated by the fan to expel the mixture.

[0068] The two most important performance indicators for range hoods are air volume and static pressure. Range hoods with high air volume have better smoke extraction effects and can quickly draw in cooking fumes; range hoods with high static pressure can overcome higher pipe network resistance, allowing them to maintain a large air volume even under high back pressure conditions.

[0069] In actual home use, external resistance is related to various factors, including the length of the flue, the number of bends in the flue, and the initial static pressure generated by other users venting smoke into the shared flue. Furthermore, the initial static pressure of the shared flue varies depending on the floor level of the user and the operating rate within the same building. Generally, in a high-rise building, the lower the floor, the higher the operating rate, and the greater the resistance in the shared flue. When external resistance differs, the operating airflow also differs. Because the external resistance is greater for lower-floor users than for higher-floor users, the operating airflow is lower for lower-floor users and higher for higher-floor users. This has the following adverse effects: for lower-floor users, the operating airflow of the range hood is lower, far below the airflow required to effectively remove cooking fumes, resulting in unsatisfactory smoke extraction.

[0070] In related technologies, to increase the air volume of a range hood, the inner and outer diameters of a single-sided air intake impeller can be increased, which leads to an increase in impeller weight and motor power; or a fan system with a double-sided air intake impeller can be used, which can make full use of the area on the motor side of the fan system to improve the airflow inside the range hood and increase the air volume; or a dual-fan range hood can be used, whose dual air intakes can be directly aimed at the stove, hoping to achieve the goal of large air volume and good smoke extraction effect.

[0071] Although the above measures increased the air intake volume, the static pressure did not improve significantly, and it was still difficult to solve the problem of high pipe network resistance and difficulty in smoke exhaust in high-rise building range hoods.

[0072] To resolve the above issues, please refer to [link / reference]. Figure 1 This application provides a range hood 2000, including a main body 300 and a fan 1000. The main body 300 serves as an outer protective component of the range hood 2000, used to support and fix the fan 1000 and other components. The main body 300 can be made of metal, including but not limited to stainless steel and aluminum, etc. This application does not limit this. When the main body 300 is made of stainless steel, it has advantages such as high strength, high temperature resistance, and environmental friendliness.

[0073] Specifically, the range hood 2000 also includes a mounting bracket 11, which can be set between the end plate of the range hood volute 100 and the main body 300, and the range hood volute 100 is fixed to the main body 300 by the mounting bracket 11.

[0074] In some embodiments of this application, such as Figure 1 As shown, the range hood 2000 also includes a check valve 13 connected to the main body 300. The check valve 13 is located at the air outlet 106. The check valve 13 allows the smoke to be discharged only from the air chamber of the range hood volute 100 to the air outlet 106 in one direction, preventing the smoke from flowing back from the air outlet 106 to the air chamber and the air inlet 105.

[0075] Specifically, the main body 300 includes a top plate 14 and a bottom plate, with the top plate 14 and bottom plate positioned opposite each other. An exhaust port 301 is located on the bottom plate, and an exhaust port 106 is located on the top plate 14. A check valve 13 is installed on the top plate 14. After the range hood 2000 is installed, the bottom plate and exhaust port 301 are close to the gas stove, while the top plate 14 is away from the gas stove. The exhaust port 106 is connected to the outside of the kitchen via the check valve 13 and a flue pipe, allowing the range hood 2000 to draw the fumes generated by the gas stove outside the kitchen. The working principle of the range hood 2000 has been disclosed in relevant technologies and will not be elaborated here.

[0076] The fan 1000 generates negative pressure suction to draw fumes from below or to the side of the range hood 2000 into the main body 300 through the exhaust port 301. The main body 300 has a flue connected to the exhaust port 301. When fumes enter the main body 300, they are drawn into the flue by the negative pressure suction of the fan 1000 and discharged outdoors or into the exhaust pipe.

[0077] The fan 1000 can be an axial flow fan, a cross flow fan, or a centrifugal fan. In this embodiment, the fan 1000 is a centrifugal fan, specifically a multi-blade centrifugal fan, for illustrative purposes.

[0078] Specifically, please refer to Figure 2 The fan 1000 includes a fan impeller assembly 200 and a flue volute 100. The flue volute 100 includes a housing 10, which forms a wind chamber 107 and an air inlet 105 and an air outlet 106 communicating with the wind chamber 107. The fan impeller assembly 200 is located inside the wind chamber 107. The housing 10 serves as the exterior component of the entire fan 1000, protecting the fan impeller assembly 200 and reducing the probability of foreign objects coming into contact with it. In addition, the housing 10 can guide the airflow, allowing the flue gas entering the main body 300 to enter the wind chamber through the air inlet 105. After the operation of the fan impeller assembly 200, the flue gas is discharged through the air outlet 106. The air outlet 106 is connected to the flue, so the flue gas is finally discharged outdoors or into the exhaust pipe through the flue.

[0079] In the embodiments of this application, please refer to Figure 2 The wind turbine assembly 200 includes a first wind turbine 20 and a second wind turbine 21. The first wind turbine 20 includes a first frame 201 and a plurality of first blades 202. The plurality of first blades 202 are distributed circumferentially along the first frame 201 to form an air intake space 2011. The second wind turbine 21 is located in the air intake space 2011 and is spaced apart from the first wind turbine 20. The axis of the first wind turbine 20 is parallel to the axis of the second wind turbine 21. The second wind turbine 21 includes a second frame 211 and a plurality of second blades 212. The plurality of second blades 212 are distributed circumferentially along the second frame 211.

[0080] When the impeller assembly 200 rotates, the flue gas entering through the air inlet enters the air intake space 2011. The flue gas undergoes initial pressurization and acceleration when passing through the second blade 212, and then undergoes further pressurization and acceleration when passing through the first blade 202. This increases the static pressure of the impeller assembly. The increased static pressure makes it easier for the flue gas to enter the flue gas duct, thereby increasing the air volume of the range hood and improving the problem of high pipe network resistance and difficulty in exhausting smoke in range hoods on lower floors.

[0081] Furthermore, the first blade 202 and the second blade 212 can have the same or opposite rotation directions. When the rotation directions are the same, the first blade 202 and the second blade 212 can both be forward-curved (also known as forward-tilted) blades and backward-curved (also known as backward-tilted) blades. When the rotation directions are opposite, the first blade 202 can be a forward-curved blade and the second blade 212 can be a backward-curved blade, or the first blade 202 can be a backward-curved blade and the second blade 212 can be a forward-curved blade. In the embodiment of this application, the rotation direction of the first blade 202 is opposite to that of the second blade 212, and further, the first blade 202 is a backward-curved blade and the second blade 212 is a forward-curved blade.

[0082] When the first blade 202 is a backward-curved blade and the second blade 212 is a forward-curved blade, the periodic overlap of the first blade 202 and the second blade 212 during the rotation of the wind turbine assembly 200 can be reduced. When the second blade 212 is a forward-curved blade, the leading edge of the blade is more curved than the trailing edge. Therefore, when the airflow passes through the second blade 212, the airflow will be thrust forward due to the curved shape of the blade, resulting in a more uniform airflow passing over the surface of the first blade 202. This not only ensures the aerodynamic performance of the first blade 202 but also reduces the rotational noise of the first blade 202 to a certain extent.

[0083] It is understandable that the first impeller 20 and the second impeller 21 can be driven by one motor or by two motors respectively. When the first impeller 20 is driven by one motor and the second impeller 21 is driven by another motor, the speed and direction of each impeller can be controlled independently, which increases the flexibility and adaptability of the equipment. When one motor fails, the other motor can still continue to work, which improves the reliability and fault tolerance of the equipment.

[0084] In this embodiment, the first impeller 20 and the second impeller 21 are controlled by a single motor. Using one motor to drive both the first impeller 20 and the second impeller 21 reduces the number of motors, simplifies the overall structure of the equipment, and lowers manufacturing costs. Under motor drive, the first impeller 20 and the second impeller 21 can rotate synchronously, which helps maintain the stability and uniformity of airflow.

[0085] When the first impeller 20 and the second impeller 21 are driven to rotate by a motor, the motor is mounted on the volute of the smoke machine (not shown in the figure), and the output shaft of the motor is driven to connect to the first frame 201. The second frame 211 is mounted on the first frame 201. In this way, the operation of the motor can drive the first impeller 20 and the second impeller 21 to rotate synchronously.

[0086] Furthermore, in this embodiment, the number of first blades 202 is n1, and the number of second blades 212 is n2. n1 satisfies: 40 ≤ n1 ≤ 70, and n2 satisfies: 10 ≤ n2 ≤ 60, and n2 < n1. That is, n1 can be a range of 40, 50, 60, 70, or any two of these, and n2 can be a range of 10, 20, 30, 40, 50, 60, or any two of these. It is understood that when n1 is 40, then 10 ≤ n2 < 40; when n2 is 60, then 60 < n1 ≤ 70. This ensures that the airflow ejected from each second blade 212 can be quickly accelerated again by the first blade 202, thereby ensuring that the airflow ejected from the first blade 202 has sufficient pressure.

[0087] Generally speaking, when n1 is twice n2, the probability of airflow ejected from multiple second blades 212 colliding with the same first blade 202 can be reduced, thereby reducing eddies and backflow phenomena. This reduces noise while ensuring that the airflow ejected from the first blade 202 has sufficient pressure.

[0088] In this embodiment, n1 and n2 are coprime numbers. When the number of the first blades 202 and the number of the second blades 212 are coprime numbers, resonance is less likely to occur between them. This makes it difficult for the vibration frequencies generated by the first impeller 20 and the second impeller 21 during rotation to coincide, thereby reducing the possibility of resonance and thus lowering the overall vibration level of the impeller assembly 200, improving the stability and reliability of the system. A stable operating environment can reduce mechanical wear and failures caused by vibration, extending the service life of the equipment. In addition, the reduced overall vibration level of the impeller assembly 200 can also effectively reduce noise caused by vibration.

[0089] It is understood that the axis of the first impeller 20 can be parallel to the axis of the second impeller 21, that is, the axis of the first impeller 20 and the axis of the second impeller 21 can coincide, or they can not coincide. In the embodiments of this application, it is preferred that the axis of the first impeller 20 and the axis of the second impeller 21 coincide. The coincident axis design may make the airflow interaction between the first impeller 20 and the second impeller 21 more favorable, reduce airflow turbulence and eddy formation, not only reduce noise, but also reduce the loss of airflow energy, and ensure that the discharged flue gas has sufficient static pressure.

[0090] In addition, the coincidence of the axis lines allows the first wind turbine 20 and the second wind turbine 21 to be connected to the generator through the same transmission system, reducing energy loss in the intermediate transmission links.

[0091] In this embodiment of the application, when the centrifugal fan is used as an example for illustrative description, the air intake direction of the centrifugal fan is axial. Specifically, in this application, the airflow enters the air intake space 2011 through the axial direction of the first impeller 20, that is, the air inlet 105 on the housing 10 is located on one side of the first blade 202 along the axial direction of the first impeller 20. In order to increase the air volume, this embodiment of the application adopts dual air intake, that is, the two air inlets 105 are symmetrically distributed on both sides of the housing 10 along the axial direction of the first impeller 20. Please refer to [link to relevant documentation]. Figure 6-7 That is, the two air inlets 105 are respectively located on both sides of the housing 10 along the axial direction of the first impeller 20, and are opposite to the air intake space 2011.

[0092] Since each first blade 202 has a leading edge surface 2021 facing the intake space 2011 and a trailing edge surface 2022 facing away from the intake space 2011, in order to facilitate airflow into the intake space 2011, please refer to... Figure 3-4 Both ends of the leading edge surface 2021 have guiding arc surfaces 202a2, which are concave towards the trailing edge surface 2022.

[0093] The concave blade design of the inlet 105 effectively alters the airflow path as it enters the fan, reducing or eliminating the vortex region caused by the direct impact of airflow on the first blade 202 at the inlet 105. This helps improve the internal flow state of the fan and enhances the uniformity of airflow distribution. By reducing the vortex region, the fan can utilize airflow energy more effectively during operation, reducing energy loss caused by vortices, thus improving the overall efficiency of the fan and reducing energy consumption. Furthermore, the reduced vortex region also lowers the startup noise of the entire impeller assembly 200.

[0094] In this embodiment, the centrifugal fan adopts a double-sided air intake method. Therefore, both ends of the leading edge surface 2021 of the first blade 202 have a guide arc surface 202a2. The guide arc surface 202a2 at one end is the first guide arc surface, and the guide arc surface 202a2 at the other end is the second guide arc surface. The first guide arc surface extends from the leading edge surface 2021 to the first end surface 2023 of the first blade 202, and the second guide arc surface extends from the leading edge surface 2021 to the second end surface 2024 of the first blade 202. In this embodiment, the first end surface 2023 and the second end surface 2024 are end surfaces distributed at both ends of the first blade 202 along the length direction of the first blade 202. The first end surface 2023 faces one air inlet 105 of the housing 10, and the second end surface 2024 faces the other air inlet 105 of the housing 10.

[0095] Thus, compared to the original flow of air along the flat leading edge 2021 to the trailing edge 2022, the first and second guide arc surfaces at both ends of the leading edge 2021 in this embodiment can more precisely control the flow path of the airflow when entering the first blade 202. This streamlined design helps to reduce airflow separation and vortex generation at the leading edge of the first blade 202, thereby improving the stability and uniformity of the airflow.

[0096] In this embodiment, the first impeller 20 and the second impeller 21 are driven to rotate by a motor. In order to reduce the size of the air intake space 2011 occupied by the motor drive, i.e., to not affect the air intake of the impeller assembly 200, the motor is generally located on one side of the entire housing 10 along the axis of the first impeller 20. Thus, the arrangement of the motor and the first frame 201 will affect the air intake of the adjacent air inlet, resulting in a smaller air intake.

[0097] The first frame 201 generally includes an upper plate, a lower plate, and a middle plate. The upper plate is located on one end face of multiple first blades 202, the lower plate is located on the other end face of multiple first blades 202, and the middle plate is located between the upper and lower plates. The upper plate, lower plate, and middle plate are all used to connect the multiple first blades 202 together. The lower plate is generally located near the motor, and in order to ensure that the intake space 2011 has a large volume, the middle plate is also designed to be near the lower plate, such as... Figure 3 As shown, since the middle plate is close to the lower plate, it may affect the design of the guide arc surface 202a2 of the first blade 202 near the lower plate. In this embodiment, the air inlet 105 on the side away from the motor is used as the first air inlet, and the air inlet 105 on the side close to the motor is used as the second air inlet for illustrative purposes. The guide arc surface 202a2 corresponding to the first air inlet is used as the first guide arc surface, and the guide arc surface 202a2 corresponding to the second air inlet is used as the second guide arc surface for illustrative purposes.

[0098] Please return and continue reading. Figure 4-5 The orthographic projections of the leading edge surface 2021 and the trailing edge surface 2022 onto the plane passing through the second end surface 2024 have corresponding leading edge lines 2021a and trailing edge lines 2022a. The line connecting the end of the leading edge line 2021a facing the intake space 2011 and the end of the trailing edge line 2022a facing the intake space 2011 is parallel to the reference plane. The reference plane is perpendicular to the second end surface 2024. The distance between the projections of the end of the leading edge line 2021a facing away from the intake space 2011 and the end of the trailing edge line 2022a facing away from the intake space 2011 onto the reference plane along the extension direction of the connecting line is W1.

[0099] Wherein, the distance between the projections of the two ends of the first guide arc surface onto the reference plane along the extension direction of the connecting line is W2, and W2 satisfies 0.1W1≤W2≤0.5W1, and W2 can be a range of 0.1W1, 0.2W1, 0.3W1, 0.4W1, 0.5W1 or any two of them.

[0100] The distance between the projections of the two ends of the second guide arc surface onto the reference plane along the direction of the connecting line is W3. W3 satisfies 0.1W1≤W3≤0.5W1. W3 can be a range consisting of 0.1W1, 0.2W1, 0.3W1, 0.4W1, 0.5W1, or any two of them.

[0101] Thus, by precisely controlling the ratio of W2 and W3 to W1, the flow path of the airflow at the leading edge of the first blade 202 can be further fine-tuned. This fine-tuning helps reduce airflow separation and vortex generation at the leading edge of the first blade 202, thereby improving the stability and uniformity of the airflow.

[0102] Reasonable W2 and W3 values ​​can reduce the stress concentration at the edge of the first blade 202 caused by airflow impact, reduce the risk of fatigue damage to the first blade 202, and thus help extend the service life of the first blade 202 and improve the reliability and durability of the fan 1000.

[0103] It should be understood that in some embodiments, the leading edge surface 2021 and the trailing edge surface 2022 of the first blade 202 may be curved surfaces. In this case, the leading edge line 2021a and the trailing edge line 2022a, which are projected onto the plane passing through the second end surface 2024, are curved lines. At this time, the line connecting the end of the leading edge line 2021a toward the air intake space 2011 and the end of the trailing edge line 2022a toward the air intake space 2011 is the line connecting the vertex of the leading edge line 2021a and the vertex of the trailing edge line 2022a.

[0104] Please continue reading. Figure 4 In this application, the projection of the first blade 202 onto the reference plane has a first guiding arc corresponding to the first guiding arc surface, and the length of the first guiding arc is R1. The projection of the first blade 202 onto the reference plane has a second guiding arc corresponding to the second guiding arc surface, and the length of the second guiding arc is R2. Since the first guiding arc surface is adjacent to the first air inlet and the second guiding arc surface is adjacent to the second air inlet, and the air volume of the first air inlet is greater than that of the second air inlet, in order to reduce manufacturing costs, the length R2 of the second guiding arc does not exceed the length R1 of the first guiding arc. In this way, the second guiding arc of appropriate length can match the air volume of the second air inlet, and at the same time, the strength of the first blade 202 can be guaranteed.

[0105] Furthermore, it is understandable that the second guide arc surface is located between the middle plate and the lower plate. In this way, when the middle plate is connected to the first blade 202, the first blade 202 has sufficient area to contact the middle plate, thus ensuring the stability of the connection between the first blade 202 and the entire first frame 201.

[0106] Since the leading edge surface 2021 of the first blade 202 is the first contact surface of the airflow when the first blade 202 is in operation, and the trailing edge surface 2022 is the exit surface of the airflow when the first blade 202 is in operation, the first guide structure 203 is provided on the leading edge surface 2021 and the trailing edge surface 2022, which can effectively reduce or eliminate eddies.

[0107] For details, please continue reading Figure 4 During the rotation of multiple first blades 202, eddies are generated as airflow enters the intake space 2011 and exits the intake space 2011 through the airflow channel between two adjacent first blades 202. By setting a first guide structure 203 on the leading edge surface 2021 or the trailing edge surface 2022 of the first blade 202, or by setting the first guide structure 203 on both the leading edge surface 2021 and the trailing edge surface 2022 of the first blade 202, the eddies during the operation of the first impeller 20 can be significantly reduced, the pressure pulsation on the surface of the first blade 202 can be reduced, and the airflow between the first blades 202 can be improved, thereby reducing the start-up noise caused by eddies.

[0108] Specifically, the first guide structure 203 is a sawtooth structure, which includes wave crests and troughs connected in sequence. The wave crests and troughs are distributed along the axial direction of the first impeller 20, that is, along the length of the first blade 202. In this way, the wave crests and troughs connected in sequence can effectively reduce the start-up noise caused by eddies.

[0109] In order to increase air volume, in this embodiment of the application, the first blade 202 is a backward-curved (also known as a backward-tilted) blade. The backward-curved blade adopts a streamlined design, which reduces fluid stall and leakage, and makes the air flow smoother, so that the air volume of the fan 1000 system can be increased under the same input power.

[0110] The embodiments of this application will further describe the volute of the range hood.

[0111] like Figures 6-7As shown, the range hood casing 100 includes a first end plate 101, a second end plate 102, and a peripheral side plate 103. The first end plate 101 and the second end plate 102 are arranged at intervals relative to each other. The peripheral side plate 103 is located between the first end plate 101 and the second end plate 102. The peripheral side plate 103 is connected to and perpendicular to the first end plate 101 and the second end plate 102. The first end plate 101, the peripheral side plate 103, and the second end plate 102 together form a wind cavity 107 and an air outlet 106. The air outlet 106 communicates with the wind cavity 107. An air inlet 105 communicating with the wind cavity 107 is provided on the first end plate 101 and / or the second end plate 102.

[0112] Both the first end plate 101 and the second end plate 102 are provided with air inlets 105 that communicate with the air cavity 107. That is, the air intake method of the flue hood volute 100 is double-sided air intake. The air inlet 105 on the first end plate 101 is the first air inlet, and the air inlet 105 on the second end plate 102 is the second air inlet. A limiting bracket 12 is installed on the second end plate 102. The limiting bracket 12 is used to install the motor. The flue gas can be drawn into the air cavity 107 through the air inlet 105 on the flue hood volute 100 under the action of the fan 1000, and then discharged from the air outlet 106.

[0113] like Figures 9-10 As shown, the outer contour of the peripheral side plate 103 projected onto the first plane includes a first arc line 103a, a clearance line 103b, and a second arc line 103c arranged sequentially and connected along the circumferential direction of the peripheral side plate 103. For example, in... Figure 10 In the diagram, the first arc 103a and the second arc 103c are dashed lines, while the avoidance line 103b is a solid line. The first plane is perpendicular to the axis of the air inlet 105, meaning the first plane is parallel to the side planes of the first end plate 101 and the second end plate 102. The radius of curvature at all points on the avoidance line 103b is greater than that at all points on the first arc 103a and the second arc 103c. This means that the radius of curvature on the avoidance line 103b is the largest compared to the first arc 103a and the second arc 103c. In other words, the curvature of the avoidance line 103b is less than that of the first arc 103a and the second arc 103c, and the avoidance line 103b is smoother overall (more closely resembling a straight line).

[0114] Specifically, the outer peripheral side of the circumferential side plate 103 includes a first arc surface 1031, a clearance surface 1032, and a second arc surface 1033 arranged sequentially and connected along the circumferential direction of the circumferential side plate 103. The two ends of the clearance surface 1032 are connected to the first arc surface 1031 and the second arc surface 1033, respectively. The orthographic projection of the first arc surface 1031 on the first plane corresponds to the first arc line 103a, the orthographic projection of the clearance surface 1032 on the first plane corresponds to the clearance line 103b, and the orthographic projection of the second arc surface 1033 on the first plane corresponds to... Corresponding to the second arc 103c, the avoidance line 103b is an arc-shaped transition line between the first arc 103a and the second arc 103c. That is to say, the avoidance surface 1032 is an arc-shaped transition between the first arc surface 1031 and the second arc surface 1033. Compared with the transition between two planes at an angle, the arc-shaped transition can prevent the two surfaces from having sharp corners at the connection. The arc-shaped transition is more in line with the flow pattern of airflow and can reduce the backflow and eddy phenomenon of flue gas caused by sharp corners (such as right angles, acute angles or obtuse angles).

[0115] It should be noted that the range hood housing 100 is installed within the installation space of the range hood 2000. Therefore, the volume of the range hood housing 100 is limited by the installation space of the range hood 2000. This is because the radius of curvature at various points on the clearance line 103b is the largest compared to the first arc 103a and the second arc 103c. Therefore, the clearance line 103b is smoother than the first arc 103a and the second arc 103c. If the side of the range hood housing 100 exceeds the installation space... In this area, the outer contour of the side of the range hood volute 100 projected onto the first plane can be set as the shape of the avoidance line 103b. This reduces the side protrusion height of the range hood volute 100, thereby reducing the volume of the range hood volute 100. At the same time, it can also improve the flow of smoke at the avoidance surface 1032 of the range hood volute 100, reduce the backflow and eddy current phenomenon of smoke at the avoidance surface 1032 of the range hood volute 100, and reduce the noise generated by the range hood volute 100 when smoking.

[0116] Furthermore, in some embodiments, the radius of curvature at various points on the second arc 103c is greater than the radius of curvature at various points on the first arc 103a. Therefore, the curvature of the second arc 103c is less than that of the first arc 103a, and the second arc 103c is smoother overall than the first arc 103a. Simultaneously, the radius of curvature at various points on the avoidance line 103b is greater than that of the second arc 103c. In other words, the radius of curvature of the avoidance line 103b is the largest compared to both the first and second arcs 103a and 103c. This means that the curvature of the avoidance line 103b is less than that of both the first and second arcs 103a and 103c, and the avoidance line 103b is smoother overall (more closely approximating a straight line).

[0117] Optionally, such as Figure 10 As shown, the air outlet 106 has an orthographic projection area on the first plane. The first end of the first arc 103a extends to the orthographic projection area of ​​the air outlet 106, and the second end of the first arc 103a is connected to the avoidance line 103b. The first end of the second arc 103c is connected to the avoidance line 103b, and the second end of the second arc 103c extends to the orthographic projection area of ​​the air outlet 106.

[0118] It is easy to understand that the first end of the first arc 103a and the second end of the second arc 103c form the orthographic projection area of ​​the air outlet 106 on the first plane. That is to say, the air outlet 106 of the range hood volute 100 is formed by the first end plate 101, the second end plate 102, the first arc surface 1031, and the second arc surface 1033. Since the peripheral side plate 103 is connected to and perpendicular to the first end plate 101 and the second end plate 102, when the overall shape of the air outlet 106 is... When the shape is square, the surface of the first end plate 101 near the second end plate 102 is perpendicular to both the first arc surface 1031 and the second arc surface 1033, and the surface of the second end plate 102 near the first end plate 101 is perpendicular to both the first arc surface 1031 and the second arc surface 1033. This allows the first end plate 101 and the second end plate 102 to be planar plate structures, which reduces the manufacturing difficulty of the range hood volute 100 and facilitates the mass production of the range hood volute 100.

[0119] Optionally, such as Figure 10 As shown, the outer contour of the peripheral side plate 103 projected onto the first plane includes two oppositely arranged avoidance lines 103b, which are located on both sides of the projected area of ​​the air outlet 106.

[0120] It should be noted that the outer peripheral side of the peripheral side plate 103 includes a first arc surface 1031, a first clearance surface 1032, a second arc surface 1033, and a second clearance surface 1032 arranged sequentially and connected along the peripheral direction of the peripheral side plate 103. The orthographic projection of the first arc surface 1031 on the first plane corresponds to the first arc line 103a, the orthographic projection of the first clearance surface 1032 on the first plane corresponds to the clearance line 103b, the orthographic projection of the second arc surface 1033 on the first plane corresponds to the second arc line 103c, and the shape of the orthographic projection of the second clearance surface 1032 on the first plane is the same as the shape of the clearance line 103b. The first clearance surface 1032 and the second clearance surface 1032 are located on both sides of the air outlet 106, that is, the air outlet 106 of the range hood volute 100 is formed by the first end plate 101, the second end plate 102, the first arc surface 1031, and the second clearance surface 1032. Figures 1-2As shown, the addition of the clearance surface 1032 on the range hood volute 100 reduces the volume of the range hood volute 100 while further improving the flow of flue gas at the clearance surface 1032, reducing the backflow and eddy current phenomenon of flue gas at the clearance surface 1032, increasing the exhaust volume of the air outlet 106, and reducing the noise generated by the range hood volute 100 when smoking.

[0121] Please see Figure 9 In some embodiments of this application, the maximum length of the first end plate 101 and the second end plate 102 along the first direction XX is H, and the maximum length of the first end plate 101 and the second end plate 102 along the second direction YY is W, where H < 600 mm and W < 600 mm; wherein, the first direction XX is parallel to the first plane and the axis of the air outlet 106, the second direction YY is perpendicular to the first direction XX, and the second direction YY is parallel to the first plane.

[0122] Further, please see Figure 10 In some embodiments of this application, the centerline of the air inlet 105 is projected onto the first plane as point O. The first plane has a first axis M, a first reference point C1, and a second reference point C2. The first axis M is parallel to the second direction YY and intersects with point O. The first reference point C1 and the second reference point C2 are symmetrically distributed about the first axis M, and the distance between the first reference point C1 and the second reference point C2 is d, where 0.25H≤d≤0.5H. The first axis M and the avoidance line 103b have a first intersection point Q. In the second direction YY, the shortest distance from the first intersection point Q to the straight line passing through the first reference point C1 and the second reference point C2 is a, where 0.2W≤a≤0.5W.

[0123] It is easy to understand that, in the first plane, the orthographic projections of the first reference point C1 and the second reference point C2 are both located inside the orthographic projection of the first end plate 101. The first axis M is taken as the x-axis, and the straight line perpendicular to the first axis M and passing through the first intersection point Q is taken as the y-axis. The coordinates of the first intersection point are the coordinates of the origin (0, 0). At this time, the coordinates of the first reference point C1 are (-a, 0.5d), and the coordinates of the second reference point C2 are (-a, -0.5d). Thus, the relative positions of the first reference point C1 and the second reference point C2 are determined.

[0124] Among them, any point on the avoidance line 103b is taken as the flow point P. The distance between the flow point P and the first reference point C1 is r1, and the distance between the flow point P and the second reference point C2 is r2, (0.25d). 2 ≤r²×r²≤(0.36d) 2 This determines the shape of the avoidance line 103b, that is, r1×r2=k 2k is a constant, and k satisfies 0.25d≤k≤0.36d.

[0125] It should be noted that, Figure 6 The middle section represents the complete curve of the Cassini oval curve. The equation of the Cassini oval curve is:

[0126] (x 2 +y 2 ) 2 -2b(x 2 -y 2 )=b 4 -c 4 (where b and c are constants).

[0127] In the first plane, the first axis M is taken as the x-axis, and the straight line passing through the first reference point C1 and the second reference point C2 is taken as the y-axis. The coordinates of the first reference point C1 are (0, 0.5d), and the coordinates of the second reference point C2 are (0, -0.5d), where d is a constant. The coordinates of the flowing point P are (x1, y1), because r1 × r2 = k. 2 ,so The equation, after simplification, becomes:

[0128] (x 2 +y 2 ) 2 -0.5d(x 2 -y 2 )=k 4 -(0.5d) 4 ;

[0129] In summary, the equation of the avoidance line 103b satisfies the equation of the Cassini oval curve, therefore the shape of the avoidance line 103b satisfies the characteristics of the Cassini oval curve, such as... Figure 11 As shown, the avoidance line 103b is a part of the Cassini oval line, which makes the flue gas flow more uniformly at the avoidance surface 1032 of the flue gas volute 100. This can reduce the velocity gradient and eddy intensity of the flue gas, reduce the turbulent kinetic energy at the avoidance surface 1032, improve the flow uniformity, and thus reduce the aerodynamic noise of the flue gas volute 100.

[0130] Please see Figure 8 In some embodiments of this application, a guide ring 24 is provided at the air inlet 105 to guide the flue gas. The guide ring 24 is arranged in an arc shape facing away from the suction cavity 107, which is conducive to the external flue gas entering the air cavity 107 from the air inlet 105 along the arc-shaped protruding surface of the guide ring 24.

[0131] In some embodiments, such as Figure 8As shown, a second flow guiding structure 25 is provided on the side of the guide ring 24 facing the centerline of the air inlet 105. That is, the first end of the guide ring 24 is connected to the inlet wall of the air inlet 105, and the second end of the guide ring 24 extends away from the air inlet 105. The second flow guiding structure 25 is located at the second end of the guide ring 24 to guide the external flue gas. The second flow guiding structure 25 can be a sawtooth structure or a beveled structure. Taking the side of the guide ring 24 facing the centerline of the air inlet 105 as an example, the sawtooth structure can disrupt the flow pattern of the vortex, thereby weakening or even eliminating the vortex phenomenon, achieving the effects of noise reduction and increased air volume.

[0132] Optionally, the guide ring 24 can be arranged in an arc shape facing away from the suction cavity 107. At the same time, the second end of the guide ring 24 is provided with a second guide structure 25 to further guide the external smoke, so that more external smoke can enter the air cavity 107 along the guide ring 24.

[0133] In some embodiments of this application, the peripheral side plate 103 is connected to and perpendicular to the first end plate 101 and the second end plate 102, that is, the connection between the peripheral side plate 103 and the first end plate 101 and the second end plate 102 is set at a 90° right angle, which facilitates the production and connection between the first end plate 101, the peripheral side plate 103 and the second end plate 102. For example, the first end plate 101 and the second end plate 102 can be planar plate structures, and the peripheral side plate 103 can be formed by bending a long strip of planar plate structure along its length direction. The side of the planar plate structure can be directly connected to the side of the peripheral side plate 103 along its width direction. This not only reduces the mold opening cost of the range hood volute 100, but also reduces the manufacturing difficulty of the range hood volute 100, thereby facilitating the mass production of the range hood volute 100.

[0134] In other embodiments of this application, the housing 10 further includes an arc-shaped transition portion, one end of the peripheral side plate 103 is connected to the first end plate 101 through the arc-shaped transition portion, and the other end of the peripheral side plate 103 is connected to the second end plate 102 through the arc-shaped transition portion. This helps to further reduce flue gas backflow and eddy current phenomena inside the range hood volute 100, and further increase the airflow at the air outlet 106, thereby reducing noise.

[0135] This application provides an example of a flue gas hood volute 100 in which the peripheral side plate 103 is connected to the first end plate 101 and the second end plate 102 via an arc-shaped transition portion.

[0136] It should also be noted that, Figure 12 The figure shows a comparison curve of the static pressure at the air outlet 106 of a range hood in related technologies and the static pressure at the air outlet 106 of the range hood 2000 of this application. Figure 12In the figure, the horizontal axis represents time, and the vertical axis represents the static pressure at the air outlet 106. The black curve in the figure represents the static pressure at the air outlet 106 of the range hood 2000 of this application at different times, and the gray curve in the figure represents the static pressure at the air outlet 106 of the range hood in the related technology at different times. Figure 12 The curve shows that the static pressure at the air outlet 106 of the range hood 2000 in this application is greater than that at the air outlet 106 of the range hood in the related art, indicating that the static pressure of the range hood 2000 in this embodiment is greater, which is more conducive to the exhaust of smoke.

[0137] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0138] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wind turbine assembly, characterized in that, include: The first wind turbine includes a first frame and multiple first blades, with the multiple first blades distributed circumferentially along the first frame to form an air intake space; as well as The second impeller is located within the air intake space and is spaced apart from the first impeller. The axis of the first impeller is parallel to the axis of the second impeller. The second impeller includes a second frame and a plurality of second blades, which are distributed circumferentially along the second frame.

2. The wind turbine assembly according to claim 1, characterized in that, The rotation direction of the first blade is opposite to that of the second blade.

3. The wind turbine assembly according to claim 1, characterized in that, The number of the first leaflets is n1, and the number of the second leaflets is n2; Where n1 satisfies: 40≤n1≤70, n2 satisfies: 10≤n2≤60, and n2<n1; And / or, n1 and n2 are coprime numbers.

4. The wind turbine assembly according to claim 1, characterized in that, The axis of the first wind turbine coincides with the axis of the second wind turbine.

5. The wind turbine assembly according to claim 1, characterized in that, Each of the first blades has a leading edge surface facing the air intake space and a trailing edge surface facing away from the air intake space. Both ends of the leading edge surface have guide arc surfaces, which are concave towards the trailing edge surface.

6. The wind turbine assembly according to claim 5, characterized in that, The flow-guiding arc surface at one end of the leading edge is a first flow-guiding arc surface, and the flow-guiding arc surface at the other end of the leading edge is a second flow-guiding arc surface. The first flow-guiding arc surface extends from the leading edge to the first end face of the first blade, and the second flow-guiding arc surface extends from the leading edge to the second end face of the first blade.

7. The wind turbine assembly according to claim 6, characterized in that, The orthographic projections of the leading edge surface and the trailing edge surface onto the plane passing through the second end face have corresponding leading edge lines and trailing edge lines. The line connecting the end of the leading edge line facing the air intake space and the end of the second leading edge line facing the air intake space is parallel to the reference plane. The reference plane is perpendicular to the second end face. The distance between the projections of the end of the leading edge line facing away from the air intake space and the end of the trailing edge line facing away from the air intake space onto the reference plane along the extension direction of the connecting line is W1. The distance between the projections of the two ends of the first guide arc surface onto the reference plane along the extension direction of the connecting line is W2, wherein W2 satisfies 0.1W1≤W2≤0.5W1; And / or, the distance between the projections of the two ends of the second guide arc surface onto the reference plane along the extension direction of the connecting line is W3, wherein W3 satisfies 0.1W1≤W3≤0.5W1; And / or, the projection of the first blade onto the reference plane has a first guiding arc corresponding to the first guiding arc surface, the length of the first guiding arc being R1, and the projection of the first blade onto the reference plane has a second guiding arc corresponding to the second guiding arc surface, the length of the second guiding arc being R2, wherein R2≤R1.

8. The wind turbine assembly according to claim 5, characterized in that, At least one of the trailing edge surface and the leading edge surface of the first blade is provided with a first flow guiding structure, which extends along the axial direction of the first impeller.

9. A fan, characterized in that, include: The wind turbine assembly according to any one of claims 1-8; and A range hood volute, the range hood volute comprising a housing, the housing forming a wind cavity and an air inlet and an air outlet communicating with the wind cavity; The wind turbine assembly is located inside the wind cavity.

10. The fan according to claim 8, characterized in that, The housing includes: First end plate; The second end plate is disposed at a distance from the first end plate; A peripheral side plate is located between the first end plate and the second end plate, and an air inlet communicating with the air cavity is provided on the first end plate and / or the second end plate; The outer contour of the peripheral side plate projected onto the first plane includes a first arc, a clearance line, and a second arc arranged sequentially and connected along the periphery of the peripheral side plate. The first plane is perpendicular to the axis of the air inlet, and the radius of curvature at each point on the clearance line is greater than the radius of curvature at each point on the first arc and the second arc.

11. The fan according to claim 10, characterized in that, The maximum length of the first end plate and the second end plate along the first direction is H, and the maximum length of the first end plate and the second end plate along the second direction is W, where H < 600 mm and W < 600 mm. Wherein, the first direction is parallel to the axial direction of the air outlet, the second direction is perpendicular to the first direction, and the second direction is parallel to the first plane.

12. The fan according to claim 11, characterized in that, The orthographic projection of the centerline of the air inlet onto the first plane is point O. The first plane has a first axis, a first reference point, and a second reference point. The first axis is parallel to the second direction and intersects with point O. The first reference point and the second reference point are symmetrically distributed about the first axis, and the distance between the first reference point and the second reference point is d, where 0.25H≤d≤0.5H. The first axis and the avoidance line have a first intersection point. In the second direction, the shortest distance from the first intersection point to the straight line passing through the first reference point and the second reference point is a, where 0.2W≤a≤0.5W. The distance between the flow point on the avoidance line and the first reference point is r1, and the distance between the flow point and the second reference point is r2, (0.25d). 2 ≤r1*r2≤(0.36d) 2 .

13. The fan according to claim 10, characterized in that, The housing further includes an arc-shaped transition section, one end of the peripheral side plate is connected to the first end plate through the arc-shaped transition section, and the other end of the peripheral side plate is connected to the second end plate through the arc-shaped transition section; Alternatively, the peripheral side plate is connected to and perpendicular to the first end plate and the second end plate.

14. A range hood, characterized in that, include: The main body has an air extraction port, and the main body has a flue connected to the air extraction port. as well as The fan according to any one of claims 9-13, wherein the fan is disposed within the main body, and the fan draws flue gas from the exhaust port into the flue.

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