Centrifugal fans, range hoods, and design methods for centrifugal fans

Abstract

This invention relates to a centrifugal fan, a range hood, and a design method for a centrifugal fan, belonging to the field of range hood technology. The centrifugal fan proposed in this invention utilizes three different designs for the first, second, and third arc-shaped protrusions to diffuse the airflow in the axial direction of the volute. Compared to the two-dimensional flow of traditional volutes, this application considers axial diffusion, thus incorporating three-dimensional flow of airflow within the volute's internal channels. Firstly, this design effectively eliminates angular vortices, facilitating airflow within the volute's internal channels. Secondly, this design more closely matches the actual flow within the volute, improving air intake efficiency. Thirdly, this design eliminates the assembly gap between the traditional range hood volute and chassis, reducing noise and improving the user experience.

Description

Technical Field

[0001] This invention relates to the field of range hood technology, and more specifically, to a centrifugal fan, a range hood, and a design method for the centrifugal fan. Background Technology

[0002] A range hood is a kitchen appliance used to absorb cooking fumes. It has become an essential appliance in many home kitchens, effectively absorbing cooking fumes and expelling them outdoors, freeing the kitchen from the nuisance of smoke. The volute of the range hood collects the air entering the impeller and directs it to the outlet, playing a role in air collection and diffusion. The impeller and volute are core components of a range hood, and their design significantly impacts the overall performance of the appliance.

[0003] The inventors discovered that the volute casing of a traditional range hood consists of multiple parts, including the top plate, volute flange, volute rear plate, casing side plate, connecting plate, volute side plate, volute front plate, casing rear plate, casing side plate, motor, and impeller. When these parts are assembled, there will always be assembly gaps. When the centrifugal fan starts, the high-speed gas moving through the casing and volute will produce a whistling sound, thereby increasing the noise of the range hood and affecting the user experience. Summary of the Invention

[0004] The present invention aims to provide a centrifugal fan, a range hood, and a design method for a centrifugal fan, which can eliminate the assembly gap between the volute and the chassis of a traditional range hood, reduce the noise of the range hood, and improve the user experience.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a centrifugal fan, comprising:

[0007] The volute includes a volute casing panel, a volute casing back plate, and a volute casing front plate. The front side of the volute casing panel is connected to the volute casing front plate, and the back side of the volute casing panel is connected to the volute casing back plate to form an air duct.

[0008] The outer edge of the volute forms a circular arc protrusion; the cross section of the circular arc protrusion includes a first circular arc segment, a second circular arc segment, and a third circular arc segment; one end of the first circular arc segment is connected to the back plate of the volute, and the other end is connected to one end of the second circular arc segment; the third circular arc segment is connected to the front plate of the volute, and the other end is connected to the other end of the second circular arc segment.

[0009] In an optional embodiment, the centrifugal fan also includes a casing, with a volute housed inside the casing, a front plate of the volute connected to the casing, and the volute enclosure, the volute back plate, and the casing forming an integral structure.

[0010] In an optional embodiment, the chassis includes a top panel, a front panel, a side panel, and a connecting plate. The top of the side panel is connected to the top panel, and the bottom of the side panel is connected to the connecting plate. The side panel includes a left side panel, a right side panel, and a back panel connected in sequence, and one side of the side panel is an open side.

[0011] The front panel of the chassis is located on the open side and is detachably connected to the chassis side panel;

[0012] The volute enclosure, volute back plate, chassis top plate, chassis enclosure, and connecting plate are integrally molded structures.

[0013] In an optional embodiment, the volute has an air outlet and an air inlet. The air inlet is disposed on the front plate of the volute. The volute surround plate, the volute back plate, and the volute front plate are connected to form an air outlet, which is located at the end of the air duct.

[0014] The connecting plate is provided with a first air vent that communicates with the air duct, and the top plate of the chassis is provided with a second air vent that communicates with the air duct. The volute enclosure, the volute back plate, and the volute front plate are connected to the edge of the second air vent on the top plate of the volute so that the second air vent matches the air outlet.

[0015] The front side of the volute casing can be detachably connected to the volute casing front plate.

[0016] In an optional implementation, the inner walls of the two transverse sides of the chassis enclosure are connected to the outer walls of the two transverse sides of the volute enclosure, so that the two transverse sides of the volute enclosure are tangent to the two transverse sides of the chassis enclosure, respectively.

[0017] Secondly, the present invention provides a range hood, including a centrifugal fan according to any of the foregoing embodiments.

[0018] Thirdly, the present invention provides a design method for a centrifugal fan, including a centrifugal fan according to any of the foregoing embodiments;

[0019] Design methods include:

[0020] Establish a first coordinate system on the radial section of the volute, with the extension direction of the volute back plate as the Y-axis, the midpoint of the volute back plate as the origin O, and the horizontal line passing through the origin O as the X-axis.

[0021] The connection point between the back plate of the volute and the first arc segment M1O1P1 is M1; the connection point between the first arc segment M1O1P1 and the second arc segment P1O3P2 is P1; the connection point between the second arc segment P1O3P2 and the third arc segment M2O2P2 is P2; the connection point between the third arc segment M2O2P2 and the front plate of the volute is M2; the center of the first arc segment M1O1P1 is O1; the center of the second arc segment P1O3P2 is O3; and the center of the third arc segment M2O2P2 is O2.

[0022] Based on the average flow rate of the volute on the current radial section, the positions of the first circular arc segment M1O1P1, the second circular arc segment P1O3P2, and the third circular arc segment M2O2P2 of the volute in the first coordinate system are calculated.

[0023] In an optional implementation, the positions of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2 of the volute in the first coordinate system are calculated based on the average flow rate of the volute on the current radial cross section, and the method further includes the following steps:

[0024] Using the coordinates of point 01 as Substituting the coordinates (X1, Y1) of P1 in the first circular arc segment M1O1P1 into the radius formula, we obtain the first governing equation:

[0025] Using the coordinates of point 02 as Substituting the coordinates (X2, Y2) of P2 in the third circular arc segment M2O2P2 into the radius formula, we obtain the second governing equation:

[0026] Substituting the coordinates of P1 (X1, Y1) and P2 (X2, Y2) into the radius formula, we obtain the third governing equation:

[0027]

[0028] Based on the first control equation, the second control equation, and the third control equation, confirm the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2.

[0029] Calculate the arc lengths of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2 based on the coordinates of P1 (X1, Y1) and P2 (X2, Y2).

[0030] Where A is the opening of the volute at the exit section with an angle θ of 360°; B is the width of the volute, which is a constant width volute.

[0031] In an optional implementation, determining the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2 based on the first control equation, the second control equation, and the third control equation further includes the following steps:

[0032] The radius of the first circular arc segment M1O1P1 is equal to the radius of the third circular arc segment M2O2P2, leading to the following fourth governing equation:

[0033]

[0034] The values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2 are confirmed by the fourth control equation mentioned above.

[0035] In an optional implementation, the arc lengths of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2 are calculated based on the coordinates P1 (X1, Y1) and P2 (X2, Y2), and the process further includes the following steps:

[0036] With point 01 as the center, point M1 is rotated clockwise by θ1 around the center 01 to obtain point P1. The arc length of the first arc segment M1O1P1 is obtained according to the central angle θ1 and arc length formula 1.

[0037] The arc length formula 1 is: L1=θ1×π×r1 / 180°;

[0038] Where L1 is the arc length of the first arc segment M1O1P1, θ1 is the central angle of the first arc segment M1O1P1, π is pi, and r1 is the radius of the first arc segment M1O1P1.

[0039] In an optional implementation, with point 02 as the center of the third circular arc segment M2O2P2, point M2 is rotated counterclockwise by θ2 around the center 01 to obtain point P2. The arc length of the third circular arc segment M2O2P2 is obtained according to the central angle θ2 and arc length formula 2.

[0040] Arc length formula 2 is: L2=θ2×π×r2 / 180°;

[0041] Where L2 is the arc length of the third arc segment M2O2P2, θ2 is the central angle of the third arc segment M2O2P2, π is pi, and r2 is the radius of the third arc segment M2O2P2.

[0042] In an optional implementation, the central angle θ1 of the first arc segment M1O1P1 ranges from 30° to 60°.

[0043] The central angle θ2 of the third arc segment M2O2P2 ranges from 30° to 60°.

[0044] In an optional implementation, point 03 is taken as the center of the second circular arc segment P1O3P2. Point P1 is rotated clockwise by θ3 around the center 03 to obtain point P2. The arc length of the second circular arc segment P1O3P2 is obtained according to the central angle θ3 and the arc length formula 3.

[0045] Arc length formula 3 is: L3=θ3×π×R3 / 180°;

[0046] Where L3 is the arc length of the second arc segment P1O3P2, θ3 is the central angle of the second arc segment P1O3P2, π is pi, and R3 is the radius of the second arc segment P1O3P2.

[0047] In an optional implementation, the step of designing the inner profile of the volute casing is further included.

[0048] In an optional implementation, designing the inner profile of the volute casing includes the following steps:

[0049] The inner profile of the volute enclosure is designed as a first profile, a second profile, and a volute profile connected in sequence. The second profile is located at the starting position of the volute profile. The second profile is set at an angle to the volute profile so that the volute enclosure forms a volute tongue. The first profile and the volute profile are part of the air outlet of the volute.

[0050] Establish a second coordinate system on the inner profile of the volute casing plate, with the center of the impeller as the origin O, the horizontal line passing through the origin O as the X-axis, and the vertical line passing through the origin O as the Y-axis.

[0051] The inner profile of the volute casing is designed based on the value of A.

[0052] In an optional implementation, the inner profile of the volute casing is designed based on the value of A, including the following steps:

[0053] Design A based on the following relationship 4. θ ;

[0054] Relation 4: A θ =E-E0;

[0055] Among them, A θ Let R be the volute opening at angle θ, R be the outer radius of the volute, R0 be the outlet radius of the impeller, and θ be the angle between any radial section and the radial section at the end of the volute profile.

[0056] The inner walls of the two sides of the chassis enclosure are designed to connect with the outer walls of the two sides of the volute enclosure, so that the two sides of the volute enclosure are tangent to the two sides of the chassis enclosure respectively. Then the lateral length of the chassis satisfies the following relationship: L=L1+L2.

[0057] Where L is the horizontal length of the chassis, L1 is the distance between the leftmost sidewall of the volute casing and the center of the impeller, and L2 is the distance between the rightmost sidewall of the volute casing and the center of the impeller.

[0058] The beneficial effects of the centrifugal fan, range hood, and centrifugal fan design method provided in the embodiments of the present invention include:

[0059] This application employs different designs for the three-segment profile of the raised arc segment (first, second, and third arc segments) to diffuse the airflow in the axial direction of the volute. Compared to the two-dimensional flow of traditional volutes, this application considers axial diffusion, thus incorporating three-dimensional flow of airflow within the volute's internal channels. Firstly, this arc segment design effectively eliminates angular vortices, facilitating airflow within the volute's internal channels. Secondly, this arc segment design more closely matches the actual flow within the volute, improving air intake efficiency. Thirdly, this arc segment design eliminates the assembly gap between the traditional range hood volute and chassis, reducing noise and enhancing the user experience. Attached Figure Description

[0060] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 This is an exploded view of the centrifugal fan provided in this embodiment;

[0062] Figure 2 This is a front view of the centrifugal fan provided in this embodiment;

[0063] Figure 3 This is a front view of the volute and impeller assembly provided in this embodiment;

[0064] Figure 4 This is a schematic diagram of the installation of the volute and impeller provided in this embodiment;

[0065] Figure 5 This is a bottom view of the volute provided in this embodiment;

[0066] Figure 6 The volute provided in this embodiment is in S n First schematic diagram of the cross-section;

[0067] Figure 7 This is a second schematic diagram of the volute in the Sn section provided in this embodiment.

[0068] Icons: 010-Centrifugal fan; 100-Volume; 110-Volume enclosure; 111-First profile; 112-Second profile; 113-Volume profile; 114-Volume tongue; 120-Volume back plate; 130-Volume front plate; 140-Air inlet; 150-Air outlet; 160-Drive component; 170-Impeller; 180-Arc segment protrusion; 181-First arc segment; 182-Second arc segment; 183-Third arc segment; 200-Chassis; 210-Chassis top plate; 220-Chassis front plate; 230-Chassis enclosure; 231-Chassis left side plate; 232-Chassis right side plate; 233-Chassis back plate; 240-Connecting plate; 241-First air outlet. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0070] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0071] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0072] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention 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 a limitation of this invention.

[0073] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0074] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0075] The following detailed description of the overall structure, working principle, and technical effects of the centrifugal fan, range hood, and centrifugal fan design method provided by the present invention, through embodiments and in conjunction with the accompanying drawings, is a practical example.

[0076] Please refer to Figure 1 The centrifugal fan 010 provided by this invention is applied to a range hood.

[0077] Please refer to Figure 1 The centrifugal fan 010 proposed in this invention includes:

[0078] The volute 100 includes a volute casing 110, a volute casing back plate 120, and a volute casing front plate 130. The front side of the volute casing 110 is connected to the volute casing front plate 130, and the back side of the volute casing 110 is connected to the volute casing back plate 120 to form an air duct.

[0079] The outer edge of the volute 100 forms an arc-shaped protrusion 180; the cross-section of the arc-shaped protrusion 180 includes a first arc segment 181, a second arc segment 182 and a third arc segment 183; one end of the first arc segment 181 is connected to the back plate 120 of the volute, and the other end is connected to one end of the second arc segment 182; the third arc segment 183 is connected to the front plate 130 of the volute, and the other end is connected to the other end of the second arc segment 182.

[0080] Understandably, this application considers the three-dimensional flow of airflow within the volute 100, which, compared to the two-dimensional flow of a traditional volute, incorporates axial diffusion. Specifically, the three arc segments 181, 182, and 183 of the arc protrusion 180 employ different designs, ultimately enabling axial diffusion within the equidistant volute 100. Firstly, this design effectively eliminates angular vortices, facilitating airflow within the volute 100's internal channels. Secondly, this design better conforms to the actual flow within the volute 100, improving air intake efficiency. Thirdly, this design eliminates the assembly gap between the traditional range hood volute 100 and the casing 200, reducing noise and enhancing the user experience.

[0081] In this embodiment, please refer to Figure 1 and Figure 2 The centrifugal fan 010 includes a casing 200.

[0082] In this embodiment, the centrifugal fan 010 also includes a casing 200, a volute 100 disposed inside the casing 200, a volute front plate 130 connected to the casing 200, and a volute enclosure 110, a volute back plate 120 and the casing 200 being an integrally formed structure.

[0083] Understandably, by integrally molding the volute enclosure 110, the volute back plate 120, and the chassis 200, the volute 100 and the chassis 200 no longer need to be assembled and fixed through connecting flanges and connectors. This eliminates the assembly gaps that occur when the volute 100 and the chassis 200 are assembled and fixed through connecting flanges and connectors, thereby reducing the noise of the range hood and improving the user experience.

[0084] In this embodiment, please refer to Figure 1 The chassis 200 includes a top panel 210, a front panel 220, a side panel 230, and a connecting plate 240. The top of the side panel 230 is connected to the top panel 210, and the bottom of the side panel 230 is connected to the connecting plate 240. The side panel 230 is a U-shaped panel, and one side of the side panel 230 is an open side. The front panel 220 is located on the open side and is detachably connected to the side panel 230.

[0085] The U-shaped chassis enclosure 230 includes a left side panel 231, a right side panel 232, and a back panel 233. The left side panel 231, the right side panel 232, and the back panel 233 are connected to form the U-shaped opening side of the chassis enclosure 230.

[0086] The chassis panel 230 has a first connecting hole on the left side panel 231 and a second connecting hole on the right side panel 232. The top panel 210 of the chassis has a third connecting hole relative to the front panel 220. The front panel 220 is detachably connected to the first connecting hole, the second connecting hole and the third connecting hole of the chassis 200 through a connector.

[0087] The connecting plate 240 is provided with a first air vent 241 that communicates with the air duct, and the top plate 210 of the chassis is provided with a second air vent that communicates with the air duct. It can be understood that the motor drives the impeller 170 to rotate, so that the oil fumes enter from the first air vent 241 of the connecting plate 240, and are driven by the impeller 170 to be discharged from the second air vent in the air duct.

[0088] In this embodiment, please refer to Figure 1 and Figure 2 The centrifugal fan 010 includes a volute 100.

[0089] In this embodiment, please refer to Figure 1 The volute 100 is installed inside the chassis 200. The volute 100 includes a volute enclosure 110, a volute back plate 120 and a volute front plate 130. The front side of the volute enclosure 110 is connected to the volute front plate 130, and the back side of the volute enclosure 110 is connected to the volute back plate 120 to form an air duct.

[0090] The front plate 130 of the volute is located on the front side of the volute enclosure 110, and the back plate 120 of the volute is on the same side as the chassis back plate 233.

[0091] The front plate 130 of the volute and the surrounding plate 110 of the volute are detachably connected.

[0092] In this embodiment, please refer to Figure 1 and Figure 2 The volute 100 has an air outlet 150 and an air inlet 140. The air inlet 140 is disposed on the front plate 130 of the volute. The volute surround plate 110, the volute back plate 120 and the volute front plate 130 are connected to form the air outlet 150, which is located at the end of the air duct. The volute surround plate 110, the volute back plate 120 and the volute front plate 130 are connected to the edge of the second air outlet on the top plate of the volute 100 so that the second air outlet matches the air outlet 150.

[0093] It is worth mentioning that, please refer to Figure 1 The volute casing 110, volute casing back plate 120, chassis top plate 210, chassis casing 230, and connecting plate 240 are integrally formed structures. The chassis front plate 220 and volute casing front plate 130 are detachably connected to chassis casing 230. The integral die-casting process eliminates the assembly gaps generated when the volute casing 100 and chassis 200 are assembled and fixed using connecting flanges and connectors, reducing noise and improving user experience. However, when installing the impeller 170 and motor inside the volute casing 100, the chassis front plate 220 and volute casing front plate 130 need to be disassembled; therefore, the chassis front plate 220 and volute casing front plate 130 are designed to be detachably connected. This setup allows for the overall assembly of the range hood and centrifugal fan 010 without affecting the overall assembly, while also reducing noise from the range hood and improving the user experience by eliminating assembly gaps.

[0094] In this embodiment, please refer to Figure 1 and Figure 2 The centrifugal fan 010 also includes a drive unit 160 and an impeller 170. The drive unit 160 and the impeller 170 are disposed in the air duct of the volute 100, and the output end of the drive unit 160 is connected to the impeller 170 for transmission.

[0095] In this embodiment, please refer to Figure 3 The inner profile of the volute enclosure 110 includes a first profile line 111, a second profile line 112 and a volute profile line 113 connected in sequence. The second profile line 112 is located at the starting position of the volute profile line 113. The first profile line 111 and the volute profile line 113 are set at an angle so that the second profile line 112 forms a volute tongue 114. The first profile line 111 and the volute profile line 113 are part of the air outlet 150 of the volute 100.

[0096] It is understandable that the volute 100, which is integrally molded by injection molding, can ensure the integrity of the inner surface contour line of the volute casing 110, thereby enabling the first profile line 111, the second profile line 112 and the volute profile line 113 to be adapted to the volute tongue 114 to form a complete centrifugal fan 010 profile line.

[0097] Among them, the volute profile 113 is logarithmic spiral.

[0098] Among them, the volute profile 113 is designed according to the principle of equal circulation, and the flow of gas in the volute 100 follows the law of constant angular momentum.

[0099] In this embodiment, please refer to Figure 3 and Figure 4 The inner walls of the two sides of the chassis enclosure 230 are connected to the outer walls of the two sides of the volute enclosure 110, so that the two sides of the volute enclosure 110 are tangent to the two sides of the chassis enclosure 230 respectively.

[0100] In this embodiment, please refer to Figure 4 The end of the first profile line 111, the back plate of the volute 120, the end of the volute profile line 113, and the front plate of the volute 130 are connected in sequence to form an air outlet 150, and the air outlet 150 has a rectangular structure.

[0101] In this embodiment, please refer to Figure 5 and Figure 6 The outer edge of the volute 100 forms an arc-shaped protrusion 180; the cross-section of the arc-shaped protrusion 180 includes a first arc segment 181, a second arc segment 182 and a third arc segment 183; one end of the first arc segment 181 is connected to the back plate 120 of the volute, and the other end is connected to one end of the second arc segment 182; the third arc segment 183 is connected to the front plate 130 of the volute, and the other end is connected to the other end of the second arc segment 182.

[0102] Understandably, by leveraging the unique advantages of injection molding, the right-angle edge of the existing sheet metal volute can be changed to the arc-shaped protrusion 180 in this application. The outer edge of the volute 100 is more easily molded into an arc-shaped protrusion 180 through injection molding, which is more conducive to the flow of air in the flow channel inside the volute 100.

[0103] Furthermore, the right-angle edges of existing sheet metal volutes are prone to flow vortices. In contrast to the right-angle edges of existing sheet metal volutes, the arc-shaped protrusion 180 in this application can effectively eliminate vortices, thereby improving the flow efficiency of the fan and reducing the flow noise inside the volute 100.

[0104] Please refer to Figure 7 This embodiment also proposes a design method for a centrifugal fan 010, including a centrifugal fan 010; the design method includes:

[0105] S1: Establish a first coordinate system on the radial section of the volute 100, with the extension direction of the volute back plate 120 as the Y-axis, the midpoint of the volute back plate 120 as the origin O, and the horizontal line passing through the origin O as the X-axis.

[0106] S2: The connection point between the volute back plate 120 and the first arc segment M1O1P1 is M1, the connection point between the first arc segment M1O1P1 and the second arc segment P1O3P2 is P1, the connection point between the second arc segment P1O3P2 and the third arc segment M2O2P2 is P2, the connection point between the third arc segment M2O2P2 and the volute front plate is M2, the center of the first arc segment M1O1P1 is O1, the center of the second arc segment P1O3P2 is O3, and the center of the third arc segment M2O2P2 is O2.

[0107] S3: Based on the average flow rate of the volute 100 on the current radial section, calculate the positions of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2 of the volute 100 in the first coordinate system.

[0108] It is understandable that this application employs the aforementioned design method to differentiate the three-segment profiles of the arc segment 181, the second arc segment 182, and the third arc segment 183 of the arc segment protrusion 180, thereby expanding the volute 100 in the axial direction. Compared to the two-dimensional flow of a traditional volute, this application considers axial expansion, thus incorporating three-dimensional flow of airflow within the volute 100's internal channels. Firstly, this design of the arc segment protrusion 180 effectively eliminates angular vortices, facilitating airflow within the volute 100's internal channels. Secondly, this design of the arc segment protrusion 180 better conforms to the actual flow within the volute 100, improving air intake efficiency. Thirdly, this design of the arc segment protrusion 180 eliminates the assembly gap between the traditional range hood volute 100 and the casing 200, reducing range hood noise and enhancing user experience.

[0109] In this embodiment, please refer to Figure 7 S3 also includes the following steps:

[0110] S31: Using the coordinates of point 01 as... Substituting the coordinates (X1, Y1) of P1 in the first circular arc segment M1O1P1 into the radius formula, we obtain the first governing equation:

[0111] S32: Using the coordinates of point 02 as... Substituting the coordinates (X2, Y2) of P2 in the third circular arc segment M2O2P2 into the radius formula, we obtain the second governing equation:

[0112] It is understandable that in S31 and S32, A is the opening of the exit section of the volute 100 at an angle θ of 360°, which can also be understood as the axial width of the volute 100 on the X-axis; B is the width of the volute back plate 120 of the volute 100.

[0113] Since the midpoint of the volute back plate 120 is the origin O and the connection point between the volute back plate 120 and the first arc segment M1O1P1 is M1, the coordinates of M1 are: The coordinates of M3 are

[0114] The axial width of the volute 100 is divided into four equal parts along the X-axis. Point 01 is located at 1 / 4 of the axial width of the volute 100, therefore the coordinates of 01 are... Point 02 is located at 3 / 4 of the axial width of the volute 100, therefore the coordinates of 02 are... Point 03 is located at 1 / 2 of the axial width of the volute 100, therefore the coordinates of 03 are...

[0115] It is understandable that, in S31, substituting line segment 01M1 into the radius formula, then... Substituting line segment 01P1 into the radius formula, then Since line segments 01P1 and 01M1 are both r1 and have the same length, we can conclude that... This leads to the first governing equation.

[0116] It is understandable that, in S32, substituting line segment 02M2 into the radius formula, then... Substituting line segment 02P2 into the radius formula, then Since line segments 02P2 and 02M2 are both r2 and have equal lengths, we can conclude that... This leads to the second governing equation.

[0117] S33: Substituting the coordinates of P1 (X1, Y1) and P2 (X2, Y2) into the radius formula, we obtain the third governing equation:

[0118] It is understandable that, in S33, substituting line segment 03P1 into the radius formula, then... Substituting line segment 03P2 into the radius formula, we get R3. 2 =(X2-A / 2) 2 +Y2 2 Since line segments 03P1 and 03P2 are both R3 and of equal length, we can conclude that... This leads to the third governing equation.

[0119] S34: Based on the first control equation, the second control equation, and the third control equation, confirm the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2.

[0120] S35: Calculate the arc lengths of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2 based on the coordinates of P1 (X1, Y1) and P2 (X2, Y2).

[0121] Where A is the opening of the volute 100 at the exit section with an angle θ of 360°; B is the width of the volute 100, which is a volute of uniform width, and B is a constant value.

[0122] It is understandable that the volute 100 of the centrifugal fan 010 adopts a uniform width design, and given that the structure of the volute 100 is determined, B is a constant value.

[0123] S34 further includes the following steps:

[0124] S341: The radius of the first circular arc segment M1O1P1 is equal to the radius of the third circular arc segment M2O2P2, leading to the following fourth governing equation:

[0125]

[0126] It is understandable that the radius of the first circular arc segment M1O1P1 is... The radius of the third arc segment M2O2P2 Therefore, we can conclude that the radius r1 of the first arc segment M1O1P1 is equal to the radius r2 of the third arc segment M2O2P2, and the lengths of line segments O1P1 and O1P2 are equal; thus... From this, we can derive the fourth control equation...

[0127] S342: Confirm the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2 using the fourth control equation above.

[0128] It is understandable that the values ​​of X1 and Y1 in coordinate P1 (X1, Y1) and the values ​​of X2 and Y2 in coordinate P2 (X2, Y2) can be obtained through the above control equations, thereby determining the positions of the first arc segment M1O1P1, the second arc segment P1O3P2 and the third arc segment M2O2P2 in the first coordinate system.

[0129] S35 further includes the following steps:

[0130] S351: With point 01 as the center, point M1 is rotated clockwise by θ1 around the center 01 to obtain point P1. The arc length of the first arc segment M1O1P1 is obtained according to the central angle θ1 and arc length formula 1.

[0131] The arc length formula 1 is: L1=θ1×π×r1 / 180°;

[0132] Where L1 is the arc length of the first arc segment M1O1P1, θ1 is the central angle of the first arc segment M1O1P1, π is pi, and r1 is the radius of the first arc segment M1O1P1.

[0133] S352: With point 02 as the center of the third circular arc segment M2O2P2, point M2 is rotated counterclockwise by θ2 around the center 01 to obtain point P2. The arc length of the third circular arc segment M2O2P2 is obtained according to the central angle θ2 and arc length formula 2.

[0134] Arc length formula 2 is: L2=θ2×π×r2 / 180°;

[0135] Where L2 is the arc length of the third arc segment M2O2P2, θ2 is the central angle of the third arc segment M2O2P2, π is pi, and r2 is the radius of the third arc segment M2O2P2.

[0136] S353: With point 03 as the center of the second circular arc segment P1O3P2, point P1 is rotated clockwise by θ3 around the center 03 to obtain point P2. The arc length of the second circular arc segment P1O3P2 is obtained according to the central angle θ3 and arc length formula 3.

[0137] Arc length formula 3 is: L3=θ3×π×R3 / 180°;

[0138] Where L3 is the arc length of the second arc segment P1O3P2, θ3 is the central angle of the second arc segment P1O3P2, π is pi, and R3 is the radius of the second arc segment P1O3P2.

[0139] It is worth mentioning that the central angle θ1 of the first arc segment M1O1P1 ranges from 30° to 60°; the central angle θ2 of the third arc segment M2O2P2 ranges from 30° to 60°.

[0140] It is understandable that by substituting the central angle θ1 of the first arc segment M1O1P1 and the central angle θ2 of the third arc segment M2O2P2 into the corresponding arc formulas, the arc lengths of the first arc segment M1O1P1 and the third arc segment M2O2P2 can be calculated.

[0141] In this embodiment, taking an equidistant volute as an example, the width of the equidistant volute is B. From the volute tongue 114 along the rotation direction of the impeller 170, the rectangular volute 100 of equal width is divided into n sections, labeled S. n Extract any cross-section and design the cross-sectional profile of the diffused volute based on the area of ​​the cross-section. The radius r1 of the first arc segment M1O1P1 and the radius r2 of the third arc segment M2O2P2 can be calculated according to Equation 1-3.

[0142] The arc radius r1 of the first arc segment M1O1P1 and the arc radius r2 of the third arc segment M2O2P2 satisfy the following relationship with the average flow rate of the volute 100 on the current radial section: Equation 1.

[0143] Relation 1:

[0144] Where r is the radius r1 of the first arc segment M1O1P1 and the radius r2 of the third arc segment M2O2P2, q s τ is the average flow rate of the volute 100 on the current radial section, D2 is the outer diameter of the impeller 170, τ2 is the section contraction coefficient, and ω is the relative velocity of the volute 100 at the same radius R.

[0145] τ2 satisfies the following relation 2:

[0146] Relation 2:

[0147] Specifically, starting from the volute tongue 114 along the rotation direction of the impeller 170, the volute casing 100 is divided into n radial sections, labeled S1 to S2. n S1 is the area of ​​the first radial section, S n S is the area of ​​the nth radial section. n-1 The area of ​​the radial section of the volute 100 before the current radial section, along the direction of airflow.

[0148] ω satisfies the following relation 3:

[0149] Relationship 3:

[0150] Among them, R n R is the outer radius of the volute 100 on the current radial section. n-1 β is the area of ​​the radial section of the volute 100 before the current radial section along the airflow direction. A For the blade inlet installation angle, β B Install the blade outlet angle.

[0151] Understandably, after determining the arc radii of the first arc segment M1O1P1, the second arc segment P1O3P2, and the third arc segment M2O2P2, the corresponding coordinate points can be controlled, and then the value of A can be determined by judging whether the current air volume has reached the set air volume and the target air volume.

[0152] In this embodiment, the design method further includes the following step, S4: designing the inner profile of the volute casing 110.

[0153] Please refer to Figure 4 S4 also includes the following steps:

[0154] S41: The inner profile of the volute enclosure 110 is designed as a first profile 111, a second profile 112 and a volute profile 113 connected in sequence. The second profile 112 is located at the starting position of the volute profile 113. The second profile 112 and the volute profile 113 are set at an angle so that the volute enclosure 110 forms a volute tongue 114. The first profile 111 and the volute profile 113 are part of the air outlet 150 of the volute 100.

[0155] S42: Establish a second coordinate system on the inner profile of the volute casing 110, with the center of the impeller 170 as the origin O, the horizontal line passing through the origin O as the X-axis, and the vertical line passing through the origin O as the Y-axis.

[0156] In S42, the X-axis located to the left of the origin O is the +X-axis, and the X-axis located to the right of the origin O is the -X-axis.

[0157] S43: Design the inner profile of the volute casing 110 based on the value of A.

[0158] S43 further includes the following steps:

[0159] S431: Design A based on the following relation 4 θ ;

[0160] Relation 4: A θ =R-R0;

[0161] Among them, A θ Let θ be the opening of the volute 100 at angle θ, R be the outer radius of the volute 100, R0 be the outlet radius of the impeller 170, and θ be the angle between any radial section and the radial section at the end of the volute profile 113.

[0162] S432: The inner walls of the two sides of the chassis enclosure 230 are designed to connect with the outer walls of the two sides of the volute enclosure 110, so that the two sides of the volute enclosure 110 are tangent to the two sides of the chassis enclosure 230 respectively. Then the lateral length of the chassis 200 satisfies the following relationship: L=L1+L2.

[0163] Where L is the lateral length of the chassis 200, L1 is the distance between the leftmost sidewall of the volute casing 110 and the center of the impeller 170, and L2 is the distance between the rightmost sidewall of the volute casing 110 and the center of the impeller 170.

[0164] It is understandable that, taking the -X axis of the second coordinate system as the starting position, when θ = 180°, the volute opening A at an angle θ = 180° is 100°. θ =R-R0=L1-R0; When θ=360°, then the volute opening A at an angle θ=360° is 100°. θ =R-R0=L2-R0.

[0165] The volute 100 adopts a constant width design, meaning B is a fixed value. With the impeller 170's axis as the center, and considering the impeller 170's rotation direction, starting from the volute tongue 114, the volute 100 is divided into n sections, labeled Si. Simultaneously, the volute profile 113 is designed according to the principle of equal circulation, ensuring that the gas flow within the volute 100 follows the law of constant angular momentum.

[0166] Correspondingly, the functional relationship between θ and R for any cross-section of the inner wall of the volute 100 is as follows:

[0167]

[0168] Where R0 is the outlet radius of impeller 170, b2 is the outlet width of impeller 170, c is the outlet circumferential velocity of impeller 170, α2 is the outlet airflow angle of impeller 170, Q is the volumetric flow rate of volute 100, and θ is the angle between any cross-section and the cross-section at the end of volute profile 113. Furthermore, given a fixed structure for volute 100, B and b2 are constants.

[0169] It is understandable that the relationship between the inner profile of the volute casing 110 and A can be calculated based on the above relationships 1-4 and functional relationships, and the inner profile of the volute casing 110 can be calculated based on the above relationships.

[0170] In summary, the centrifugal fan 010, range hood, and centrifugal fan 010 design method provided by this invention, through different designs of the three-segment profiles of the arc segment 180 (first arc segment 181, second arc segment 182, and third arc segment 183), diffuses the volute 100 in the axial direction. Compared to the two-dimensional flow of a traditional volute, this application considers axial diffusion, thus considering the three-dimensional flow of airflow within the volute 100's internal channels. Firstly, this design of the arc segment 180 effectively eliminates angular vortices, facilitating airflow within the volute 100's internal channels. Secondly, this design of the arc segment 180 better conforms to the actual flow within the volute 100, improving air intake efficiency. Thirdly, this design of the arc segment 180 eliminates the assembly gap between the traditional range hood volute 100 and the casing 200, reducing noise and improving the user experience.

[0171] Furthermore, the inner surface contour lines of the volute casing 110 are designed as a first profile line 111, a second profile line 112, and a volute profile line 113. The volute casing 100, which is integrally formed by injection molding, can ensure the integrity of the inner surface contour lines of the volute casing 110.

[0172] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A centrifugal fan, characterized in that, include: The volute (100) includes a volute surround plate (110), a volute back plate (120), and a volute front plate (130). The front side of the volute surround plate (110) is connected to the volute front plate (130), and the back side of the volute surround plate (110) is connected to the volute back plate (120) to form an air duct. The outer edge of the volute (100) forms an arc-shaped protrusion (180); the cross-section of the arc-shaped protrusion (180) includes a first arc segment (181), a second arc segment (182) and a third arc segment (183); one end of the first arc segment (181) is connected to the back plate (120) of the volute, and the other end is connected to one end of the second arc segment (182); the third arc segment (183) is connected to the front plate (130) of the volute, and the other end is connected to the other end of the second arc segment (182); The chassis (200) has the volute (100) disposed inside the chassis (200), the volute front plate (130) is connected to the chassis (200), and the volute side plate (110), the volute back plate (120) and the chassis (200) are integrally formed structures; The chassis (200) includes a front panel (220) and a side panel (230). One side of the side panel (230) is an open side. The front panel (220) is located on the open side and is detachably connected to the side panel (230). The front side of the volute side panel (110) is detachably connected to the front panel (130).

2. The centrifugal fan according to claim 1, characterized in that, The chassis (200) includes a top panel (210) and a connecting plate (240). The top of the chassis panel (230) is connected to the top panel (210), and the bottom of the chassis panel (230) is connected to the connecting plate (240). The chassis panel (230) includes a left side panel (231), a right side panel (232), and a back panel (233) connected in sequence. The volute enclosure plate (110), the volute back plate (120), the chassis top plate (210), the chassis enclosure plate (230), and the connecting plate (240) are integrally formed.

3. The centrifugal fan according to claim 2, characterized in that, The volute (100) has an air outlet (150) and an air inlet (140). The air inlet (140) is disposed on the front plate (130) of the volute. The volute enclosure (110), the volute back plate (120) and the volute front plate (130) are connected to form the air outlet (150). The air outlet (150) is located at the end of the air duct. The connecting plate (240) is provided with a first air vent (241) communicating with the air duct, and the top plate of the chassis (210) is provided with a second air vent communicating with the air duct. The volute enclosure (110), the volute back plate (120) and the volute front plate (130) are connected to the edge of the second air vent of the top plate of the volute (100) so that the second air vent cooperates with the air outlet (150).

4. The centrifugal fan according to claim 2, characterized in that, The inner walls of the two sides of the chassis enclosure (230) are connected to the outer walls of the two sides of the volute enclosure (110) so that the two sides of the volute enclosure (110) are tangent to the two sides of the chassis enclosure (230) respectively.

5. A range hood, characterized in that, Includes the centrifugal fan (010) as described in any one of claims 1-4.

6. A design method for a centrifugal fan, characterized in that, Includes the centrifugal fan (010) as described in any one of claims 1-4; The design method includes: A first coordinate system is established on the radial section of the volute (100), with the extension direction of the volute back plate (120) as the Y-axis, the midpoint of the volute back plate (120) as the origin O, and the horizontal line passing through the origin O as the X-axis. The volute back plate (120) and the first arc segment The connection point is M1, and the first arc segment The connection point between the second arc segment P1O3P2 and the third arc segment is P1. The connection point is P2, and the third arc segment The connection point with the front plate (130) of the volute is M2, and the first arc segment The center of the first arc segment is O1, the center of the second arc segment P1O3P2 is O3, and the center of the third arc segment... The center of the circle is O2; The first arc segment of the volute (100) is calculated based on the average flow rate of the volute (100) on the current radial cross section. The second circular arc segment P1O3P2 and the third circular arc segment The position in the first coordinate system.

7. The design method for a centrifugal fan according to claim 6, characterized in that, The first arc segment of the volute (100) is calculated based on the average flow rate of the volute (100) on the current radial cross section. The second circular arc segment P1O3P2 and the third circular arc segment At the position of the first coordinate system, the following steps are also included: Using the coordinates of point 01 as （ ), the first arc segment Substituting the coordinates (X1, Y1) of P1 into the radius formula, we obtain the first governing equation: ; Using the coordinates of point 02 as （ ), the third arc segment Substituting the coordinates (X2, Y2) of P2 into the radius formula, we obtain the second governing equation: ; Substituting the coordinates of P1 (X1, Y1) and P2 (X2, Y2) into the radius formula, we obtain the third governing equation: ； Based on the first control equation, the second control equation, and the third control equation, confirm the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2. The first arc segment is calculated based on the coordinates of P1 (X1, Y1) and P2 (X2, Y2). The arc lengths of the second arc segment P1O3P2 and the third arc segment M2O2P2; Where A is the angle of the volute (100). B is the opening of the 360° outlet section; B is the width of the volute (100), which is a volute of equal width and B is a constant value.

8. The design method of the centrifugal fan according to claim 7, characterized in that, The process of determining the values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2 based on the first, second, and third control equations also includes the following steps: The first arc segment The radius and the third circular arc segment Since the radii are equal, the following fourth governing equation is derived: The values ​​of X1 and Y1 in coordinates (X1, Y1) of P1 and the values ​​of X2 and Y2 in coordinates (X2, Y2) of P2 are confirmed by the fourth control equation mentioned above.

9. The design method of the centrifugal fan according to claim 7, characterized in that, The first arc segment is calculated based on the coordinates of P1 (X1, Y1) and P2 (X2, Y2). The arc lengths of the second arc segment P1O3P2 and the third arc segment M2O2P2 also include the following steps: With point 01 as the center, point M1 is rotated clockwise by θ1 around the center 01 to obtain point P1. The first arc segment is obtained according to the central angle θ1 and arc length formula 1. The arc length; The arc length formula 1 is: L1 = θ1 × π × r1 / 180°; Wherein, L1 is the first arc segment The arc length, θ1 is the first arc segment The central angle, π is pi, and r1 is the first arc segment. radius, .

10. The design method of the centrifugal fan according to claim 9, characterized in that, Point 02 is the third circular arc segment. Point M2 is the center of the circle. Rotating point M2 counterclockwise by θ2 around the center O1 yields point P2. The third arc segment is then derived using the central angle θ2 and arc length formula 2. The arc length; Arc length formula 2 is: L2 = θ2 × π × r2 / 180°; Wherein, L2 is the third circular arc segment. The arc length, θ2 is the arc length of the third circular arc segment. The central angle, π is pi, and r2 is the third arc segment. radius, .

11. The design method of the centrifugal fan according to claim 10, characterized in that, The first arc segment The central angle θ1 ranges from 30° to 60°. The third arc segment The central angle θ2 ranges from 30° to 60°.

12. The design method of the centrifugal fan according to claim 10, characterized in that, With point O3 as the center of the second circular arc segment P1O3P2, point P1 is rotated clockwise by θ3 around the center O3 to obtain point P2. The arc length of the second circular arc segment P1O3P2 is obtained according to the central angle θ3 and arc length formula 3. The arc length formula 3 is: L3 = θ3 × π × R3 / 180°; Where L3 is the arc length of the second arc segment P1O3P2, θ3 is the central angle of the second arc segment P1O3P2, π is pi, and R3 is the radius of the second arc segment P1O3P2. .

13. The design method for a centrifugal fan according to claim 7, characterized in that, It also includes the following steps: Design the inner profile of the volute casing.

14. The design method for a centrifugal fan according to claim 13, characterized in that, The design of the inner profile of the volute casing (110) includes the following steps: The inner profile of the volute enclosure (110) is designed as a first profile line (111), a second profile line (112) and a volute profile line (113) connected in sequence. The second profile line (112) is located at the starting position of the volute profile line (113). The second profile line (112) and the volute profile line (113) are set at an angle so that the volute enclosure (110) forms a volute tongue (114). The first profile line (111) and the volute profile line (113) are part of the air outlet (150) of the volute (100). A second coordinate system is established on the inner surface profile line of the volute casing (110), with the center of the impeller (170) as the origin O, the horizontal line passing through the origin O as the X-axis, and the vertical line passing through the origin O as the Y-axis. The inner profile of the volute casing (110) is designed based on the value of A.

15. The design method for a centrifugal fan according to claim 14, characterized in that, The inner profile of the volute casing plate (110) is designed based on the value of A, including the following steps: Design based on the following relationship 4 ; Relation 4: ; in, At angle The opening of the volute (100) at the location, where R is the outer radius of the volute (100). Let be the outlet radius of the impeller (170). The angle between any of the radial sections and the radial section at the end of the volute profile (113); The inner walls of the two transverse sides of the chassis enclosure (230) are designed to connect with the outer walls of the two transverse sides of the volute enclosure (110), so that the two transverse sides of the volute enclosure (110) are tangent to the two transverse sides of the chassis enclosure (230). Then, the transverse length of the chassis (200) satisfies the following relationship: ; Where L is the lateral length of the chassis (200), L1 is the distance between the leftmost sidewall of the volute casing (110) and the center of the impeller (170), and L2 is the distance between the rightmost sidewall of the volute casing (110) and the center of the impeller (170).

Images