Volute design method, fan and range hood

Abstract

The invention relates to the technical field of volute design, in particular to a volute design method, a fan and a range hood. The volute comprises a first end plate, a second end plate and a surrounding plate, the edge, in the width direction, of the surrounding plate is connected with the first end plate and the second end plate correspondingly, and the design method comprises the steps that the surrounding plate is divided into a plurality of element structures from a volute tongue of the volute in the spiral expansion direction of the volute based on a preset circumferential angle; a middle section molded line and an edge section molded line of the radial section of the element structure in the width direction are drawn, the edge section molded line is a first arc molded line, and the radius of the first arc molded line corresponding to the element structure is gradually increased in the spiral expansion direction of the volute from a volute tongue of the volute; and designing the volute according to the middle section molded line and the edge section molded line of the element structure. According to the design method of the volute, the aerodynamic performance of airflow in the volute can be optimized under the condition that the flowing space of a main flow area of the volute is not occupied, and therefore the noise problem of the volute is effectively solved.

Description

Technical Field

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

[0002] When using a kitchen range hood with a built-in centrifugal fan, during actual operation, there is a very obvious dynamic-static interference between the airflow at the impeller outlet and the wall of the volute. This interference can lead to significant eddy noise and rotational noise, thus affecting the user experience.

[0003] In related technologies, the common approach to improve the noise problem of the volute is to optimize its radial cross-sectional profile. However, due to the centrifugal axial intake and radial exhaust design, most of the airflow cannot complete a 90° deformation after entering the impeller due to inertia. At this time, there is a large angle of attack between the airflow and the impeller, which occupies the main flow space of the airflow in the volute, causing airflow turbulence and thus generating a lot of noise. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to propose a design method for a volute that optimizes the aerodynamic performance of the airflow within the volute without encroaching on the main flow space, thereby improving the noise problem of the volute.

[0005] According to the design method of the volute according to an embodiment of the present invention, the volute includes a first end plate, a second end plate, and a surrounding plate. The edges of the surrounding plate in the width direction are respectively connected to the first end plate and the second end plate. The design method includes: dividing the surrounding plate from the volute tongue along the spiral expansion direction of the volute into multiple basic structures based on a preset circumferential angle; drawing the radial cross-section of the basic structure in the width direction, including the middle section profile and the edge section profile, wherein the edge section profile is a first circular arc profile, and the radius of the first circular arc profile corresponding to the basic structure gradually increases from the volute tongue along the spiral expansion direction of the volute; designing the volute according to the middle section profile and the edge section profile of the basic structure, wherein an impeller is coaxially installed inside the volute, and an auxiliary circular profile is set based on the outer diameter of the impeller. The maximum distance from which the auxiliary circular profile extends outward along the diameter direction to the middle section profile of the corresponding basic structure is greater than or equal to the height of a preset multiple of the basic profile, wherein the minimum value of the preset multiple is two, and the basic profile is the profile corresponding to the cross-section of the basic structure composed of the middle section profile and the edge section profile in the width direction.

[0006] According to the design method of the volute according to an embodiment of the present invention, the design method further includes: limiting the ratio between the radius of the first arc-shaped line and the width of the volute by a first preset ratio range and a second preset ratio range, wherein the first preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the first basic structure arranged from the volute tongue along the spiral expansion direction of the volute, and the second preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the last basic structure arranged from the volute tongue along the spiral expansion direction of the volute, and the ratio within the first preset ratio range is less than the ratio within the second preset ratio range.

[0007] According to the design method of the volute according to an embodiment of the present invention, the radial section of the basic structure is provided with an auxiliary horizontal profile in the width direction, the middle section profile is composed of at least one line segment, and the middle section profile and the edge section profile are smoothly transitioned.

[0008] According to the design method of the volute according to an embodiment of the present invention, when the middle section profile is composed of a single line segment, the middle section profile is a horizontal profile or a second circular arc profile.

[0009] According to the design method of the volute according to an embodiment of the present invention, when the middle section profile is a horizontal profile, the middle section profile partially overlaps with the auxiliary horizontal profile.

[0010] According to the design method of the volute according to an embodiment of the present invention, when the middle section profile is a second arc profile, the radius of the second arc profile corresponding to the basic structure gradually decreases from the volute tongue along the spiral expansion direction of the volute.

[0011] According to the design method of the volute according to an embodiment of the present invention, the design method further includes: limiting the ratio between the radius of the second arc-shaped line and the width of the volute by a third preset ratio range and a fourth preset ratio range, wherein the third preset ratio range is used to limit the ratio of the radius to the width of the second arc-shaped line corresponding to the first basic structure arranged from the volute tongue along the spiral expansion direction of the volute, and the fourth preset ratio range is used to limit the ratio of the radius to the width of the second arc-shaped line corresponding to the last basic structure arranged from the volute tongue along the spiral expansion direction of the volute, and the ratio within the third preset ratio range is greater than the ratio within the fourth preset ratio range.

[0012] According to the design method of the volute according to an embodiment of the present invention, when the middle section profile is composed of two line segments, the middle section profile includes a first sub-profile and a second sub-profile, the first sub-profile and the second sub-profile are connected and have a connection point, the connection point being located at the midpoint of the auxiliary horizontal profile.

[0013] According to the design method of the volute according to an embodiment of the present invention, the end of the first basic structure near the volute tongue forms a first line segment with the midpoint of the impeller, and the end of the volute tongue away from the air outlet of the volute forms a second line segment with the midpoint of the impeller. The included angle between the first line segment and the second line segment is within a preset angle range.

[0014] According to the design method of the volute according to an embodiment of the present invention, the preset angle range is [0°, 10°].

[0015] According to the design method of the volute according to an embodiment of the present invention, the preset range of the circumferential angle is [15°, 100°].

[0016] According to the design method of the volute according to an embodiment of the present invention, the volute tongue of the volute is divided into multiple basic structures along the spiral expansion direction according to a preset angle. The middle section profile and the edge section profile are further determined in the width direction of the radial section of the basic structure. The shape of the volute is designed according to the middle section profile and the edge section profile so that the airflow entering the volute has a uniform flow velocity in the four connection areas of the volute enclosure plate and the first end plate and the second end plate. This further improves the airflow inside the volute and thus improves the noise problem of the volute fan.

[0017] To achieve the above objectives, a second aspect of the present invention provides a fan that includes the volute designed in the volute design method of the first aspect, and has the same beneficial effects as the volute designed in the volute design method.

[0018] To achieve the above objectives, a third aspect of the present invention provides a range hood that includes the fan described in the second aspect and has corresponding beneficial effects.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 A flowchart illustrating the design method of the volute provided in this embodiment of the invention; Figure 2 This is a schematic diagram of the volute structure provided in an embodiment of the present invention; Figure 3 A schematic diagram of a radial cross-section of a basic structure provided in an embodiment of the present invention; Figure 4 A schematic diagram of the radial cross-section of another basic structure provided in an embodiment of the present invention; Figure 5 A schematic diagram of the radial cross-section of another basic structure provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the auxiliary circular line provided in an embodiment of the present invention.

[0021] Reference numerals: 10-First end plate; 20-Second end plate; 30-Surrounding plate; 40-Voltage tongue; 50-Impeller; 60-Air outlet; 70-Auxiliary circular line. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The design method of the volute according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0024] refer to Figure 1 The flowchart shows the design method of the volute provided in the embodiment of the present invention.

[0025] Step S101: Based on a preset circumferential angle, the surrounding plate 30 is divided into multiple basic structures from the volute tongue 40 along the spiral expansion direction of the volute.

[0026] Step S102: Draw the radial cross-section of the basic structure in the width direction, including the middle section profile and the edge section profile. The edge section profile is the first circular arc profile, and the radius of the first circular arc profile corresponding to the basic structure gradually increases from the volute tongue 40 along the spiral expansion direction of the volute.

[0027] Step S103: Design the volute based on the middle and edge profiles of the basic structure.

[0028] Specifically, refer to Figure 2 The diagram shows the structure of the volute provided in this embodiment of the invention. The volute includes a first end plate 10, a second end plate 20, and a surrounding plate 30. When the volute is laid flat, the first end plate 10 can be the upper end plate, and the second end plate 20 can be the lower end plate. Both the first end plate 10 and the second end plate 20 are planar plates used to limit the overall shape of the volute. The surrounding plate 30 is connected to the first end plate 10 and the second end plate 20 respectively at its edge in the width direction (i.e., the axial direction of the volute). The first end plate 10, the second end plate 20, and the surrounding plate 30 together constitute the overall external structure of the volute.

[0029] The volute tongue 40 profile and the gap between the volute tongue 40 and the fan have a significant impact on the aerodynamic noise of the fan. Without changing the structure of the volute tongue 40, it is necessary to divide the enclosure plate 30 into multiple basic structures along the spiral expansion direction of the volute, starting from the volute tongue 40 and based on a preset circumferential angle. The number of basic structures should be greater than or equal to 3. It can be understood that the more basic structures there are, the less turbulence generated by the airflow in the volute, but the manufacturing and assembly processes of the volute will be more complex, and the manufacturing cost will increase accordingly. Conversely, the fewer basic structures there are, the more turbulence generated by the airflow in the volute, but the manufacturing and assembly processes of the volute will be relatively simpler, and the manufacturing cost will be relatively lower. Therefore, the specific number of basic structures can be determined based on the application scenario and application experience, and is not specifically limited here.

[0030] The radial cross-sectional portion of the basic structure on the volute is shown in the figure below. Figure 3 As shown, draw the middle section profile BC and the edge section profile AB / CD in the width direction of the cross section, and determine the final structure of the volute based on the drawn middle section profile and edge section profile.

[0031] Among them, the edge segment profile, as the connecting edge end of the enclosure plate 30 and the first end plate 10 and the second end plate 20, needs to be set as the first arc profile so that the enclosure plate 30 and the first end plate 10 and the second end plate 20 have a smooth transition. At the same time, since the airflow in the volute airflow channel can continuously converge and increase along the circumference, the airflow is greater closer to the volute outlet. Therefore, it is necessary to set the radius of the first arc profile corresponding to the basic structure to gradually increase from the volute tongue 40 along the spiral expansion direction of the volute, so as to suppress the expansion of the low-speed airflow region in the volute and suppress the diffusion of the high turbulent kinetic energy region, thereby reducing the pulsation intensity and thus reducing the aerodynamic noise generated by the volute.

[0032] It should be noted that, Figure 3 Chinese R i3 It represents the radius of the first circular arc in the i-th primitive structure.

[0033] As an optional embodiment, the preset circumferential angle range is [15°, 100°].

[0034] Specifically, the preset circumferential angle needs to be greater than or equal to 15° so as to avoid the structural part of the volute tongue 40 when determining the basic structure. At the same time, the preset circumferential angle needs to be less than or equal to 100° so that the setting of the basic structure can have the maximum benefit and the optimal manufacturing cost.

[0035] As an optional embodiment, the design method further includes: limiting the ratio between the radius of the first arc-shaped line and the width of the volute by a first preset ratio range and a second preset ratio range, wherein the first preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the first basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute, and the second preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the last basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute, and the ratio within the first preset ratio range is less than the ratio within the second preset ratio range.

[0036] Specifically, there is a proportional relationship between the radius of the first arc-shaped line and the width of the volute, which can further suppress the expansion and pulsation intensity of the airflow, thereby suppressing the generation of aerodynamic noise. The ratio between the radius of the first arc-shaped line and the width of the volute includes a first preset ratio range and a second preset ratio range. The first preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the first basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute. The second preset ratio range is used to limit the ratio of the radius to the width of the first arc-shaped line corresponding to the last basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute.

[0037] It should be noted that the ratio within the first preset ratio range is less than the ratio within the second preset ratio range. In this embodiment of the invention, the first preset ratio range is preferably not less than 0.0307 and not greater than 0.0376, and the second preset ratio range is preferably not less than 0.148 and not greater than 0.181.

[0038] Taking the enclosure 30 with 10 basic structural elements as an example, the ratio between the radius of the first arc-shaped line and the width of the volute is shown in Table 1: Table 1

[0039] Among them, R 13 R represents the radius of the first circular arc in the first primitive structure. 23 R represents the radius of the first arc in the second primitive structure, and so on. 103 H represents the radius of the first circular arc in the tenth basic structure, while H represents the width of the volute.

[0040] As an optional embodiment, the radial section of the basic structure is provided with auxiliary horizontal profiles in the width direction, the middle section profile is composed of at least one line segment, and the middle section profile and the edge section profile are smoothly transitioned.

[0041] Specifically, the radial section of the basic structure has auxiliary horizontal profiles in the width direction (such as...). Figure 3 China E i F i As shown, where i represents the i-th basic structure), the auxiliary horizontal profile is used to determine the geometry of the radial section of the basic structure so that the airflow state inside the volute meets the expectation. The middle section profile in the width direction consists of at least one line segment, which can be a straight line or a curve. In order to make the shape of the volute enclosure 30 smooth and the airflow inside the volute stable, the connection between the middle section profile and the edge section profile needs to be smooth.

[0042] As an optional embodiment, when the middle section profile consists of a single line segment, the middle section profile is either a horizontal profile or a second circular arc profile.

[0043] As an optional embodiment, when the middle section profile is a horizontal profile, the middle section profile partially overlaps with the auxiliary horizontal profile.

[0044] Specifically, when the middle section profile consists of a single line segment, the middle section profile can be... Figure 3 The second arc-shaped line shown can also have a middle section line that is... Figure 4 The horizontal profile shown here partially overlaps with the auxiliary horizontal profile, and the horizontal profile and the edge profile need to be tangent to each other so that the edge profile can form a smooth transition with the middle profile. The middle profile is a horizontal profile, which facilitates the processing of the volute mold, reduces the manufacturing process difficulty and manufacturing cost, while retaining the arc of the edge profile to enable the acceleration and vortex suppression effect in the connection area between the first end plate 10 and the second end plate 20 and the surrounding plate 30.

[0045] As an optional embodiment, when the middle section profile is the second arc profile, the radius of the second arc profile corresponding to the basic structure gradually decreases from the volute tongue 40 along the spiral expansion direction of the volute.

[0046] As an optional embodiment, the design method further includes: limiting the ratio between the radius of the second arc-shaped line and the width of the volute by a third preset ratio range and a fourth preset ratio range, wherein the third preset ratio range is used to limit the ratio of the radius to the width of the second arc-shaped line corresponding to the first basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute, and the fourth preset ratio range is used to limit the ratio of the radius to the width of the second arc-shaped line corresponding to the last basic structure arranged from the volute tongue 40 along the spiral expansion direction of the volute, and the ratio within the third preset ratio range is greater than the ratio within the fourth preset ratio range.

[0047] Specifically, such as Figure 3As shown, when the middle section profile is a second arc profile, the radius of the second arc profile on the radial cross-section of multiple basic structures starts from the volute tongue 40 and decreases sequentially along the spiral expansion direction of the volute. Simultaneously, there is a ratio between the radius of the second arc profile and the width of the volute, which can further suppress the expansion and pulsation intensity of the airflow, thereby suppressing the generation of aerodynamic noise. The ratio between the radius of the second arc profile and the width of the volute includes a third preset ratio range and a fourth preset ratio range. The third preset ratio range is used to limit the ratio of the radius to the width of the second arc profile corresponding to the first basic structure arranged along the spiral expansion direction of the volute, starting from the volute tongue 40. The fourth preset ratio range is used to limit the ratio of the radius to the width of the second arc profile corresponding to the last basic structure arranged along the spiral expansion direction of the volute, starting from the volute tongue 40.

[0048] It should be noted that, Figure 3 Chinese R i4 It represents the radius of the second circular arc in the i-th primitive structure.

[0049] It should be noted that the ratio within the third preset ratio range is greater than the ratio within the fourth preset ratio range. In this embodiment of the invention, the third preset ratio range is preferably not less than 3.351 and not greater than 4.095, and the fourth preset ratio range is preferably not less than 0.759 and not greater than 0.928.

[0050] Taking the enclosure 30 with 10 basic structural elements as an example, the ratio between the radius of the second arc-shaped line and the width of the volute is shown in Table 2: Table 2

[0051] Among them, R 14 R represents the radius of the second arc in the first primitive structure. 24 R represents the radius of the second arc in the second primitive structure, and so on. 104 H represents the radius of the second arc in the tenth basic structure, while H also represents the width of the volute.

[0052] It should be noted that the first and second circular arc profiles of the radial cross-section of the volute's basic structure need to be adjusted multiple times based on the axial position of the arcs to ensure that the airflow in the internal flow channel of the volute is on the optimal flow path. The radii of the first and second circular arc profiles are limited to the values ​​shown in Tables 1 and 2 by the width of the volute. This is mainly because the airflow rate within the volute's flow channel continuously converges and increases circumferentially. As the volute approaches its outlet, the decrease in the curvature of the arcs can limit the expansion of the low-speed region and suppress the diffusion of the high-turbulent kinetic energy region, thereby reducing the intensity of pressure pulsation and decreasing the noise generated by the volute.

[0053] refer to Figure 5 This is a schematic diagram of the radial cross-section of another basic structure provided in an embodiment of the present invention.

[0054] As an optional embodiment, when the intermediate section profile consists of two line segments, the intermediate section profile includes a first sub-profile and a second sub-profile, the first sub-profile and the second sub-profile are connected and have a connection point, the connection point being located at the midpoint of the auxiliary horizontal profile.

[0055] Specifically, the intermediate section profile can also be composed of two line segments. In this case, the intermediate section profile includes a first sub-profile and a second sub-profile. The midpoint P of the auxiliary horizontal line is set as the connection point of the first sub-profile and the second sub-profile. The first sub-profile and the second sub-profile are symmetrical about the perpendicular line passing through the midpoint. The airflow inside the volute can diffuse evenly to both sides under the shape of the enclosure 30 formed by the first sub-profile and the second sub-profile, avoiding the deviation of the airflow channel shape of the volute, which would lead to uneven airflow velocity and pressure distribution. At the same time, it can also greatly simplify the processing mold of the volute.

[0056] As an optional embodiment, an impeller 50 is coaxially mounted inside the volute. An auxiliary circular line 70 is set based on the outer diameter of the impeller 50. The maximum distance from which the auxiliary circular line 70 extends outward along the diameter direction to the middle section profile of the corresponding basic structure is greater than or equal to the height of the basic profile of a preset multiple. The minimum value of the preset multiple is two. The basic profile is the profile of the cross section of the basic structure composed of the middle section profile and the edge section profile in the width direction.

[0057] Specifically, an impeller 50 is coaxially mounted inside the volute. When the impeller 50 rotates, the blades on the impeller 50 cause the gas inside the volute to rotate and generate extremely high circumferential speed. This allows the airflow to be guided from the inlet at the center of the impeller 50 to the outer edge of the impeller 50 under the action of centrifugal force, and then flow to the outlet of the volute along the flow channel shape of the volute.

[0058] The auxiliary circular line 70 is set based on the outer diameter of the impeller 50, such as... Figure 6 As shown, the profile of the cross-section of the basic structure in the width direction is the basic profile. The maximum distance that the auxiliary circular profile 70 extends along the diameter direction needs to be greater than or equal to the height of the basic profile by a preset multiple, that is... ,in, Let be the maximum distance along the diameter of the auxiliary circular line 70 corresponding to the i-th primitive structure. Let n1m1 be the height of the primitive line corresponding to the i-th primitive structure. For example, n1m1 is the maximum distance extended along the diameter direction of the auxiliary circular line 70 corresponding to the first primitive structure, n1r1 is the height of the primitive line corresponding to the first primitive structure, and the others n2-n are the heights of the primitive lines. 10 m2-m 10and r2-r 10 For details, please refer to the descriptions of n1m1 and n1r1 above, which will not be repeated here. It should be noted that n0m0 and n0r0 can be used as the starting point for dividing the first primitive structure.

[0059] It should be noted that, The preset multiple is set to a minimum of two to avoid the construction of the basic element profile encroaching on the flow space of the main flow area of ​​the volute. As an optional embodiment, the endpoint of the first basic element structure near the volute tongue 40 forms a first line segment with the midpoint of the impeller 50, and the end of the volute tongue 40 away from the air outlet 60 forms a second line segment with the midpoint of the impeller 50. The included angle between the first and second line segments is within a preset angle range.

[0060] As an optional embodiment, the preset angle range is [0°, 10°].

[0061] Specifically, the second line segment formed by the end of the volute tongue 40 away from the air outlet 60 and the midpoint of the impeller 50, and the first line segment formed by the end of the first basic structure near the volute tongue 40 and the midpoint of the impeller 50, have a preset angle. The preset angle is in the range of [0°, 10°]. By designing the preset angle, not only can the structure of the volute tongue 40 be changed, thus avoiding the need to re-mold and increase the manufacturing cost of the volute, but it can also effectively reduce the collision between the airflow at the beginning end of the volute flow channel and the volute tongue 40 area, thereby reducing the operating noise.

[0062] According to the design method of the volute according to an embodiment of the present invention, the volute tongue of the volute is divided into multiple basic structures along the spiral expansion direction according to a preset angle. The middle section profile and the edge section profile are further determined in the width direction of the radial section of the basic structure. The shape of the volute is designed in a regular manner according to the middle section profile and the edge section profile, so that the airflow entering the volute has a uniform flow velocity in the four connection areas of the volute enclosure plate and the first end plate and the second end plate, which further makes the airflow have better fluidity inside the volute, thereby improving the noise problem of the volute fan.

[0063] Based on the same concept, corresponding to the above-mentioned volute design method, the present invention also provides a fan, which uses the volute manufactured by the above-mentioned volute design method, and the fan has the beneficial effects corresponding to the above-mentioned volute design method, which will not be elaborated here.

[0064] Based on the same concept, corresponding to the aforementioned fan, the present invention also provides a range hood that uses the aforementioned fan and has the same beneficial effects as the aforementioned fan, which will not be elaborated here.

[0065] Furthermore, the other components and functions of the volute, fan, and range hood in the embodiments of the present invention are known to those skilled in the art, and will not be described in detail here to reduce redundancy.

[0066] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0067] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0068] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] In the description of this invention, it should be understood that the terms "midpoint", "width", "horizontal", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and 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.

[0070] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0071] In this invention, unless otherwise explicitly specified or limited in the embodiments, the term "connected" and similar terms appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can refer to the internal connection of two components, or the interaction between two components. Those skilled in the art will be able to understand the specific meaning of the above terms in this invention based on the specific implementation.

[0072] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for designing a volute, characterized in that, The volute includes a first end plate, a second end plate, and a surrounding plate. The surrounding plate is connected to the first end plate and the second end plate respectively at its edges in the width direction. The design method includes: Based on a preset circumferential angle, the enclosure is divided into multiple basic structures from the volute tongue along the spiral expansion direction of the volute. Draw the radial cross-section of the basic structure in the width direction, including the middle section profile and the edge section profile, wherein the edge section profile is a first circular arc profile, and the radius of the first circular arc profile corresponding to the basic structure gradually increases from the volute tongue along the spiral expansion direction of the volute. The volute is designed based on the profile lines of the middle and edge segments of the basic structure. The impeller is coaxially mounted inside the volute. An auxiliary circular line is set based on the outer diameter of the impeller. The maximum distance from which the auxiliary circular line extends outward along the diameter direction to the middle section profile of the corresponding basic structure is greater than or equal to the height of the basic profile of a preset multiple. The minimum value of the preset multiple is two. The basic profile is the profile of the cross section of the basic structure composed of the middle section profile and the edge section profile in the width direction.

2. The design method of the volute according to claim 1, characterized in that, The design method further includes: The ratio between the radius of the first arcuate line and the width of the volute is limited by a first preset ratio range and a second preset ratio range. The first preset ratio range is used to limit the ratio of the radius of the first arcuate line corresponding to the first basic structure arranged from the volute tongue along the spiral expansion direction of the volute to the width of the volute. The second preset ratio range is used to limit the ratio of the radius of the first arcuate line corresponding to the last basic structure arranged from the volute tongue along the spiral expansion direction of the volute to the width of the volute. The ratio within the first preset ratio range is smaller than the ratio within the second preset ratio range.

3. The design method of the volute according to claim 1, characterized in that, The radial section of the basic structure has an auxiliary horizontal profile in the width direction. The middle section profile is composed of at least one line segment, and the middle section profile and the edge section profile have a smooth transition.

4. The design method of the volute according to claim 3, characterized in that, When the intermediate section profile is composed of a single line segment, the intermediate section profile is either a horizontal profile or a second circular arc profile.

5. The design method of the volute according to claim 4, characterized in that, When the middle section profile is the horizontal profile, the middle section profile partially overlaps with the auxiliary horizontal profile.

6. The design method of the volute according to claim 4, characterized in that, When the middle section profile is the second circular arc profile, the radius of the second circular arc profile corresponding to the basic structure gradually decreases from the volute tongue along the spiral expansion direction of the volute.

7. The design method of the volute according to claim 6, characterized in that, The design method further includes: The ratio between the radius of the second arcuate line and the width of the volute is limited by a third preset ratio range and a fourth preset ratio range. The third preset ratio range is used to limit the ratio between the radius of the second arcuate line corresponding to the first basic structure arranged from the volute tongue along the spiral expansion direction of the volute and the width of the volute. The fourth preset ratio range is used to limit the ratio between the radius of the second arcuate line corresponding to the last basic structure arranged from the volute tongue along the spiral expansion direction of the volute and the width of the volute. The ratio in the third preset ratio range is greater than the ratio in the fourth preset ratio range.

8. The design method of the volute according to claim 3, characterized in that, When the intermediate section profile is composed of two line segments, the intermediate section profile includes a first sub-profile and a second sub-profile, the first sub-profile and the second sub-profile are connected and have a connection point, the connection point being located at the midpoint of the auxiliary horizontal profile.

9. The design method of the volute according to claim 2 or 7, characterized in that, The first basic structure forms a first line segment with the end of the volute tongue near the midpoint of the impeller, and forms a second line segment with the end of the volute tongue away from the air outlet of the volute shell and the midpoint of the impeller. The included angle between the first line segment and the second line segment is within a preset angle range.

10. The design method of the volute according to claim 9, characterized in that, The preset angle range is [0°, 10°].

11. The design method of the volute according to claim 1, characterized in that, The preset circumferential angle has a range of [15°, 100°].

12. A fan, characterized in that, It includes a volute, which is designed by the design method of any one of claims 1-11.

13. A range hood, characterized in that, Includes the wind turbine as described in claim 12.

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