Volute, fan, household appliance, and design method

Abstract

A volute, a fan, a household appliance, and a design method. The volute (1) is provided with an air inlet and an air outlet; in a longitudinal cross section of the volute (1), the profile of the volute (1) comprises: an arc segment (121) and a spiral segment (122) connected to each other; a portion corresponding to the arc segment (121) and a portion corresponding to the spiral segment (122) are both configured to define a fan chamber of the fan; the spiral segment (122) is located on the side of the arc segment (121) close to the air outlet; and the spiral segment (122) is smoothly connected to the arc segment (121) and extends toward the air outlet, thereby solving the technical problem in the prior art of insufficient aerodynamic performance of fans.

Description

Casings, Fans, Home Appliances and Design Methods

[0001] This application claims priority to the patent application filed on March 27, 2025, with China National Intellectual Property Administration, application number 202510376271.5, entitled "Vortex, Fan, Household Appliance and Design Method". Technical Field

[0002] This application relates to the field of wind turbine technology, and more specifically, to a volute, a wind turbine, a household appliance, and a design method. Background Technology

[0003] Currently, multi-blade centrifugal fans are widely used in household appliances such as air conditioners, air purifiers, and range hoods due to their high total pressure and low noise characteristics. However, these appliances have limited internal space, and in addition to the fan, they also need to accommodate other critical components, resulting in strict limitations on the fan design space.

[0004] However, in traditional centrifugal fan designs, the volute profile often uses a logarithmic spiral or an Archimedean spiral. While these profiles meet the basic functional requirements of the fan to some extent, their performance is insufficient under limited space. Optimizing the volute profile, especially its matching with the impeller, is crucial for fan design. Traditional volute profiles, under space constraints, often fail to fully utilize available space, resulting in a limited impeller diameter, which in turn affects the fan's work capacity, aerodynamic performance, and reduces total pressure and efficiency. Summary of the Invention

[0005] The main objective of this application is to provide a volute, a fan, a household appliance, and a design method to solve the technical problem of insufficient aerodynamic performance of fans in the prior art.

[0006] To achieve the above objectives, according to one aspect of this application, a volute is provided; the volute has an air inlet and an air outlet; in a longitudinal section of the volute, the profile of the volute includes:

[0007] Interconnected arc segments and spiral segments, the corresponding parts of the arc segments and the corresponding parts of the spiral segments are used to form the fan cavity of the fan; the spiral segment is located on the side of the arc segment near the air outlet, the spiral segment is smoothly connected to the arc segment and extends towards the air outlet.

[0008] Furthermore, the profile of the volute also includes:

[0009] The arc segment is smoothly connected to the side of the circular arc segment away from the spiral segment. The arc segment can be a circular arc segment or a spiral segment.

[0010] Furthermore, the arc segment is a circular arc segment, and the average radius of the arc segment is greater than or equal to the average radius of the circular arc segment; wherein, the average radius of the arc segment is the average of all position radii calculated along the circular arc segment from the start point to the end point; the average radius of the circular arc segment is the average of all position radii calculated along the circular arc segment 121 from the start point to the end point.

[0011] Furthermore, the arc segment is a circular arc segment, and along this circular arc segment from the starting point to the ending point, the ratio of the maximum value to the minimum value of the radius at all positions is greater than or equal to 1 and less than or equal to 1.1.

[0012] Furthermore, the arc segment is a spiral segment, which can be a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral.

[0013] Furthermore, the profile of the volute also includes:

[0014] The first air outlet section and the second air outlet section are set opposite to each other to form an air outlet, and the connecting end of the second air outlet section extends out of the connecting end of the first air outlet section.

[0015] The first air outlet section is connected to the end of the arc section that is away from the spiral section, and the second air outlet section is connected to the end of the spiral section that is away from the arc section.

[0016] Furthermore, the initial azimuth angle of the side of the circular arc segment furthest from the helical segment is... Alternatively, the azimuth angle of the side of the circular arc segment closest to the spiral segment is... Alternatively, along the extension direction of the arc segment, the arc segment has multiple sequentially connected arc segments, each with a maximum radius of R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min Alternatively, the initial azimuth angle of the side of the circular arc segment furthest from the helical segment is... Along the extension direction of the arc segment, the arc segment has multiple sequentially connected arc segments, and the maximum radius of each arc segment is R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R minAlternatively, the azimuth angle of the side of the circular arc segment closest to the spiral segment is... Along the extension direction of the arc segment, the arc segment has multiple sequentially connected arc segments, and the maximum radius of each arc segment is R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min Alternatively, the initial azimuth angle of the side of the circular arc segment furthest from the helical segment is... The azimuth angle of the side of the circular arc segment closest to the spiral segment is... Along the extension direction of the arc segment, the arc segment has multiple sequentially connected arc segments, and the maximum radius of each arc segment is R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min .

[0017] Furthermore, the spiral segments can be logarithmic spirals, Archimedean spirals, or variable-angle spirals.

[0018] Furthermore, along the extension direction from the arc segment to the air outlet of the fan, the spiral segment is a variable-angle spiral with a gradually expanding spiral angle.

[0019] Furthermore, the polar coordinate expression for the helical segment is: in, Let α be the terminating azimuth angle at the junction of the circular arc segment and the helical segment, α be the helical angle of the helical segment, and a, b, c, and d be parameters describing the variation of the helical angle with the azimuth angle. The azimuth angle is in polar coordinates.

[0020] Furthermore, L is the preset width value. Azimuth The polar radius of the point on the corresponding volute profile.

[0021] According to another aspect of this application, a fan is provided, comprising: the volute provided above.

[0022] Furthermore, the fan also includes a fan blade, which is set inside the fan cavity. The periphery of the fan blade is set opposite to the arc segment, the average radius of the arc segment is R1, and the average radius of the outer contour of the fan blade is R2, R1=R2+t, t=t0*R2, 0.1≤t0≤0.2.

[0023] According to another aspect of this application, a household appliance is provided, comprising: the aforementioned fan, wherein the household appliance is any one of an air conditioner, an air purifier, and a range hood.

[0024] According to another aspect of this application, a design method for the profile of a wind turbine volute is provided, applicable to the volute provided above; the design method includes:

[0025] The profile of the volute includes both circular arc segments and helical segments;

[0026] Determine the polar coordinate equations corresponding to the circular arc segment and the spiral segment respectively, so as to obtain the volute profile model equation;

[0027] Based on the volute profile model equation, with flow coefficient and efficiency as optimization objectives, the optimal volute profile is determined by a genetic algorithm.

[0028] Furthermore, based on the volute profile model equation, with flow coefficient and efficiency as optimization objectives, the optimization includes: using the volute profile model equation as a constraint condition for the genetic algorithm, and setting the optimization objective of the genetic algorithm as... Where ψ is the flow coefficient and η is the efficiency; or, the optimal volute profile can be determined using a genetic algorithm, including: determining the azimuth angle at the connection point of the circular arc segment and the spiral segment, or the average radius of the circular arc segment; or, based on the volute profile model equation, with the flow coefficient and efficiency as optimization objectives, including: using the volute profile model equation as a constraint condition for the genetic algorithm, and setting the optimization objective of the genetic algorithm as... Determining the optimal volute profile using a genetic algorithm includes: determining the azimuth angle at the connection point of the circular arc segment and the spiral segment, or the average radius of the circular arc segment.

[0029] Furthermore, the equation for the volute profile model is: The constraints also include in, The starting azimuth angle of the side of the circular arc segment 121 that is away from the spiral segment 122; The azimuth angle of the side of the circular arc segment 121 closest to the spiral segment 122; For the azimuth angle of the volute type 1 line The corresponding point's polar radius; R2 is the average radius of the outer contour of blade 2; t is the volute tongue clearance, t=t0*R2, 0.1≤t0≤0.2; α is the helix angle of helix segment 122; a, b, c, d are parameters describing the change of helix angle with azimuth angle; is the azimuth angle in polar coordinates; L is the preset width value.

[0030] Furthermore, the polar coordinate expression for the optimal volute profile is:

[0031] By employing a volute profile design combining arc and spiral segments, the aerodynamic performance of the fan can be significantly improved. The use of arc segments allows for a larger impeller diameter, enhancing the fan's work capacity. Furthermore, the smooth transition from the arc segments to the spiral segments ensures the continuity and stability of airflow during the transition, reducing flow losses and improving the fan's total pressure and efficiency. Secondly, the spiral segments further optimize the diffusion and mixing process of airflow within the volute. This not only improves the total pressure coefficient at high flow rates but also reduces the entropy production rate (i.e., internal flow losses) of the entire system, thereby increasing fan efficiency and achieving a dual improvement in airflow and total pressure within the same spatial dimensions. This design ensures aerodynamic performance even with a smaller fan size, enabling the fan to achieve airflow levels comparable to or exceeding those of conventional volute fans within a smaller lateral dimension, providing a direction for the miniaturization of centrifugal fans. Therefore, the technical solution of this application can solve the technical problem of insufficient aerodynamic performance of existing fans. Attached Figure Description

[0032] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0033] Figure 1 shows a schematic diagram of the profile of the volute and the outer contour of the blades according to Embodiment 1 of this application;

[0034] Figure 2 shows a schematic diagram comparing the profile of the volute and the blade outline of the fan according to Embodiment 1 of this application with the profile of the volute and the blade outline of a conventional fan.

[0035] Figure 3 shows a schematic diagram comparing the pq (total pressure-flow rate) curves of the fan provided according to Embodiment 2 of this application and a conventional fan;

[0036] Figure 4 shows a schematic diagram comparing the flow field entropy productivity distribution of the fan provided according to Embodiment 2 of this application and a conventional fan;

[0037] Figure 5 shows a schematic diagram comparing the total pressure coefficient-flow coefficient-efficiency characteristic curves of the fan provided according to Embodiment 2 of this application and a conventional fan;

[0038] Figure 6 shows a schematic diagram comparing the volute profiles of a fan provided according to Embodiment 2 of this application and a conventional fan at the same fan capacity level.

[0039] The above-mentioned figures include the following reference numerals: 1. Volute; 11. Air outlet section; 111. First air outlet section; 112. Second air outlet section; 113. Third air outlet section; 12. Air guide section; 121. Arc section; 122. Spiral section; 123. Arc-shaped section; 2. Fan blade; 31. Before optimization, volute; 32. Before optimization, fan blade. Detailed Implementation

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] As shown in Figures 1 to 6, Embodiment 1 of this application provides a volute 1, which has an air inlet and an air outlet. On the longitudinal section of the volute 1, the profile of the volute 1 includes interconnected arc segments 121 and spiral segments 122. The portions corresponding to the arc segments 121 and the portions corresponding to the spiral segments 122 are used to form the fan cavity of the fan. The spiral segments 122 are located on the side of the arc segments 121 near the air outlet. The spiral segments 122 are smoothly connected to the arc segments 121 and extend toward the air outlet.

[0042] The volute 1 provided in Embodiment 1 of this application, through its profile design combining arc segments 121 and spiral segments 122, significantly improves the aerodynamic performance of the fan. The use of arc segments 121 allows the impeller of the fan blades 2 to have a larger diameter, thereby enhancing the fan's work capacity. Furthermore, the smooth connection between the arc segments 121 and the spiral segments 122 ensures the continuity and stability of the airflow during the transition from the arc segments 121 to the spiral segments 122, reducing flow losses and improving the fan's total pressure and efficiency. Secondly, the spiral segments 122 further optimize the diffusion and mixing process of the airflow within the volute 1. This not only improves the fan's total pressure coefficient at high flow rates but also reduces the entropy production rate within the entire system, i.e., internal flow losses, thereby improving fan efficiency and achieving a dual increase in airflow and total pressure within the same spatial dimensions. This design ensures the aerodynamic performance of the fan even with a smaller size, allowing it to achieve airflow levels comparable to or even exceeding those of conventional volute fans within a smaller lateral dimension. This provides a direction for the miniaturization of centrifugal fans. Therefore, the volute provided in this embodiment can solve the technical problem of insufficient aerodynamic performance in existing fans.

[0043] It should be noted that the longitudinal section of the volute 1 refers to the cross-sectional view formed by cutting perpendicularly through the geometric center of the volute 1 along the direction of the central axis of the wind turbine, as shown in Figure 1. The longitudinal section of Figure 1 shows the profile of the volute 1 and the outer contour of the blade 2.

[0044] Specifically, the profile of the volute 1 includes an outlet section 11 and a guide section 12. The outlet section 11 includes a first outlet segment 111, a third outlet segment 113, and a second outlet segment 112 connected in sequence. The portion of the outlet section 11 corresponding to the fan forms the fan's outlet. The guide section 12 includes an arc segment 121 and a spiral segment 122. The arc segment 121 and the spiral segment 122 are smoothly connected and together form the fan cavity of the fan. The fan blade 2 is located inside the fan cavity. The longitudinal sectional view in Figure 1 shows the shape and connection method of the arc segment 121 and the spiral segment 122, as well as important design parameters such as the volute opening A, the impeller diameter R2 of the fan blade 2, and the radius R1 of the arc segment 121. The volute opening A refers to the difference between the volute outlet width and the width of the narrowest part of the volute (usually the volute wall near the impeller inlet).

[0045] Specifically, the profile of the volute 1 also includes an arc segment 123, which smoothly connects to the side of the circular arc segment 121 away from the spiral segment 122. The arc segment 123 can be either a circular arc segment or a spiral segment. This structural arrangement aims to optimize the airflow efficiency within the volute 1. Whether a circular arc segment or a spiral segment is used for the arc segment 123, the profile of the volute 1 can be adjusted according to the actual operating conditions and requirements of the fan to achieve better aerodynamic performance. The circular arc segment provides more stable fluid inlet conditions, allowing for a larger impeller diameter, while the spiral segment better matches the spiral characteristics of the spiral segment 122. The optimized selection of these two options further improves the fan's total pressure and efficiency.

[0046] Specifically, when the arc segment 123 is a circular arc segment, the average radius of the arc segment 123 is greater than or equal to the average radius of the circular arc segment 121. In this way, the volute 1 can provide a larger diameter space for the impeller, thereby improving the impeller's work capacity and enhancing the overall air volume and total pressure of the fan.

[0047] It should be noted that the average radius of arc segment 123 refers to the average of the radii calculated along the arc segment from the start point to the end point. The average radius of arc segment 121 refers to the average of the radii calculated along the arc segment 121 from the start point to the end point.

[0048] It should be noted that when arc segment 123 is a circular arc segment, the ratio of the maximum to the minimum value of the radius at all positions along the circular arc segment from the starting point to the ending point is greater than or equal to 1 and less than or equal to 1.1.

[0049] Specifically, when the arc segment 123 is a spiral segment, the arc segment 123 is a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral. This effectively improves the diffusion characteristics of the airflow within the volute 1, reduces flow losses, and enhances the total pressure and efficiency of the fan.

[0050] Specifically, the profile of the volute 1 also includes a first air outlet segment 111 and a second air outlet segment 112 arranged opposite to each other. The first air outlet segment 111 and the second air outlet segment 112 are spaced apart to form an air outlet, and the connecting end of the second air outlet segment 112 extends out of the connecting end of the first air outlet segment 111. The connecting end of the first air outlet segment 111 is connected to the end of the arc segment 121 away from the spiral segment 122, and the connecting end of the second air outlet segment 112 is connected to the end of the spiral segment 122 away from the arc segment 121. With this structural arrangement, the arc segment 121 is positioned at the beginning of the air guide section 12 of the volute 1's profile (equivalent to the beginning of the fan cavity flow channel, i.e., the side of the flow channel near the air inlet). The flow velocity in this initial part of the flow channel is relatively low. Positioning the arc segment 121 in this part to increase the impeller diameter reduces gas flow loss within the fan cavity and maximizes airflow.

[0051] Specifically, the initial azimuth angle of the side of the circular arc segment 121 that is away from the spiral segment 122 is... This structural design allows for better integration with the outlet section 11, ensuring sufficient space to accommodate a larger impeller diameter, thereby improving the impeller's work capacity and enhancing the fan's air volume and total pressure.

[0052] Specifically, the azimuth angle of the side of the circular arc segment 121 closest to the spiral segment 122 is... With this structural design, the larger the proportion of the arc segment 121, the larger the impeller diameter can be accommodated, resulting in a stronger impeller work capacity. However, the reduced proportion of the spiral segment 122 used for diffusion leads to increased flow losses, meaning the output fan capacity may not necessarily increase. When the proportion of the arc segment 121 is relatively small, the increase in impeller work capacity outweighs the increase in flow losses, thus improving fan capacity. However, as the arc segment 121 further increases, the internal flow field of the fan deteriorates drastically. In the most extreme case, for the same fan size, the aerodynamic performance of a pure annular volute centrifugal fan is significantly lower than that of a conventional volute fan. Therefore, the fan's output capacity exhibits a trend of first increasing and then decreasing with increasing impeller diameter, indicating the existence of an optimal impeller diameter, i.e., an optimal... The value of the azimuth angle is set within [135°, 225°], which can better balance the impeller's work capacity and flow losses, so that the fan has better aerodynamic performance.

[0053] It should be noted that the aforementioned starting azimuth and azimuth angles are based on the polar coordinate axis in Figure 1. The origin of this polar coordinate axis is at the center of the cross-section of the fan blade 2 of the fan to which the volute 1 belongs, and the fan blade 2 is located inside the fan cavity of the fan. The polar axis extends horizontally.

[0054] Specifically, along the extension direction of the arc segment 121, the arc segment 121 has multiple sequentially connected arc segments, and the maximum radius of each arc segment is R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min This structural design ensures that the arc segment 121 is a perfect circle (R). max =R min (corresponding case) or an approximately circular arc portion (0 < (R) max -R min ) / R min (The case corresponding to ≤0.1) can ensure sufficient space to accommodate a larger impeller diameter, thereby improving the impeller's work capacity, optimizing the matching between the impeller and the volute 1, and achieving higher aerodynamic efficiency.

[0055] Specifically, the spiral segment 122 is a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral. This structural arrangement allows for diffusion of the gas flow within the fan cavity through the spiral segment 122, optimizing the flow field within the fan cavity, reducing gas flow losses, and improving the aerodynamic performance of the fan.

[0056] In this embodiment, along the extension direction from the arc segment 121 to the fan outlet, the spiral segment 122 is a variable-angle spiral with a gradually expanding spiral angle. Thus, the spiral design of a conventional volute 1 is either based on the assumption of equal circulation (logarithmic spiral) or the assumption of equal velocity (Archimedean spiral). These are both based on a one-dimensional ideal steady flow and assume that the airflow rapidly diffuses within the volute 1 and then achieves uniform mixing. However, actual gas is not ideal and flows in three-dimensional space, resulting in complex flow conditions. The mixing degree of the airflow within the flow channel is not necessarily uniform. Therefore, using a spiral with a varying spiral angle can better reduce airflow losses and better reflects the actual operating conditions of the fan.

[0057] Specifically, the polar coordinate expression for the spiral segment 122 is: in, Let α be the terminating azimuth angle at the junction of the circular arc segment 121 and the spiral segment 122, α be the spiral angle of the spiral segment 122, and a, b, c, and d be parameters describing the change of the spiral angle with the azimuth angle. The azimuth angle is in polar coordinates. Thus, by constructing the polar coordinate expression for the spiral segment 122, the shape of the variable-angle spiral can be accurately described, facilitating the optimized design of the volute 1 profile, thereby effectively reducing airflow losses within the volute 1 and improving the total pressure and efficiency of the fan.

[0058] It should be noted that the helix angle α of the helix segment 122 is the angle between the tangent line at a point on the helix segment 122 and the perpendicular line to the polar radius line corresponding to the point, as shown in Figure 1.

[0059] Specifically, L is the preset width value. Azimuth The extreme radius of the point on the corresponding volute type 1 line. This structural design is adopted to take into account that the actual installation environment of the fan is a confined space with limited installation space dimensions. By limiting the preset width value, it is possible to determine the optimal shape of the air guide section 12 in the confined space, thereby meeting the actual production requirements.

[0060] Embodiment 2 of this application provides a fan, which includes the volute provided in Embodiment 1.

[0061] The fan provided in Embodiment 2 of this application improves the total pressure of the fan and reduces internal flow losses by designing the profile of the fan casing 1, thereby increasing the fan's efficiency. For household appliances, this means reducing energy consumption, lowering operating costs, and improving overall energy efficiency while providing the same or better performance. It also means achieving higher airflow and total pressure within the same or smaller equipment space. Using the fan provided in Embodiment 1, the overall equipment can be made more compact while maintaining high performance. This is particularly important for space-constrained household environments, making appliance designs more space-saving, easier to install and maintain, and improving user convenience. Therefore, the fan provided in this embodiment solves the technical problem of insufficient aerodynamic performance in existing fans.

[0062] Specifically, the fan is a centrifugal fan.

[0063] In this embodiment, the fan also includes a fan blade 2, which is disposed within the fan cavity. The periphery of the fan blade 2 is positioned opposite to the arc segment 121. The average radius of the arc segment 121 is R1, and the average radius of the outer contour of the fan blade 2 is R2, where R1 = R2 + t, t = t0 * R2, and 0.1 ≤ t0 ≤ 0.2. With this structural arrangement, by setting the distance t between the fan blade 2 and the arc segment 121, and the proportional relationship between t and the impeller radius R2, it can be ensured that the gap between the fan blade 2 and the volute 1 is neither too large, leading to airflow leakage, nor too small, leading to increased airflow resistance. This achieves efficient airflow transmission between the volute 1 and the fan blade 2. The implementation effect is that during fan operation, the airflow transmission efficiency between the volute 1 and the fan blade 2 is significantly improved. Due to the reasonable setting of the gap t, the airflow transmission efficiency is high, reducing leakage and resistance, thereby improving the total pressure and efficiency of the fan. Furthermore, this configuration also facilitates the adjustment of the average radius of the arc segment 121 to change the diameter of the outer contour of the accommodated blade 2, thereby improving the impeller's work capacity and enhancing the aerodynamic performance of the fan.

[0064] It should be noted that the average radius of the arc segment 121 refers to the average of the radii at all positions along the arc segment 121 from the starting point to the ending point. The average radius of the circumference of the impeller 2 refers to the average of the radii at all positions along the outer contour of the impeller from the starting point to the ending point.

[0065] Embodiment 3 of this application provides a household appliance, which includes the fan provided in Embodiment 2. The household appliance is any one of an air conditioner, an air purifier, and a range hood.

[0066] The household appliance provided in Embodiment 3 of this application improves the total pressure of the fan and reduces internal flow losses by designing the profile of the fan casing 1, thereby increasing the fan's efficiency. For household appliances, this means reducing energy consumption, lowering operating costs, and improving overall energy efficiency while providing the same or better performance. It also means achieving higher airflow and total pressure within the same or smaller equipment space. Using the fan provided in Embodiment 1, the overall equipment can be made more compact while maintaining high performance. This is particularly important for space-constrained home environments, making the design of household appliances more space-saving, easier to install and maintain, and improving user convenience. Therefore, the household appliance provided in this embodiment can solve the technical problem of insufficient aerodynamic performance of fans in the prior art.

[0067] Embodiment 4 of this application provides a design method for the profile of a wind turbine volute, applicable to the volute provided in Embodiment 1; the design method includes: making the profile of the volute 1 include a circular arc segment 121 and a spiral segment 122; determining the polar coordinate equations corresponding to the circular arc segment 121 and the spiral segment 122 respectively to obtain the volute profile model equation; and determining the optimal volute profile using a genetic algorithm based on the volute profile model equation, with the flow coefficient and efficiency as optimization objectives.

[0068] The design method for the fan volute profile provided in Embodiment 4 of this application introduces the concepts of circular arc segments 121 and spiral segments 122, and accurately describes the shapes of these two segments using polar coordinate equations, more accurately reflecting the actual flow characteristics of the airflow inside the volute 1. Using a genetic algorithm, with flow coefficient and efficiency as optimization objectives, it helps achieve the optimal match between the volute 1 and the impeller within a limited space, enabling the fan to achieve miniaturization while maintaining high performance. Traditional variable-angle spiral design requires specifying the initial and final spiral angles, then interpolating at 0.5π, π, and 1.5π using empirical formulas, and finally obtaining the complete variable-angle spiral through cubic polynomial fitting. However, the use of a genetic algorithm can quickly select the optimal solution from a large number of possible design schemes, greatly shortening the development cycle and reducing development costs. This method avoids the resource waste that may result from traditional trial-and-error methods and improves design efficiency. Furthermore, compared to traditional design methods, the designed profile better matches the actual airflow, resulting in less airflow loss. Therefore, the design method of the fan volute profile provided in this embodiment can solve the technical problem of insufficient aerodynamic performance of fans in the prior art.

[0069] It should be noted that the genetic algorithm used is the NSGA-II algorithm (Non-dominated sorting genetic algorithm II). The steps used in the genetic algorithm are the same as those in the conventional NSGA-II algorithm, the difference lies in the different optimization objectives and constraints.

[0070] Specifically, based on the volute profile model equation, the method with flow coefficient and efficiency as optimization objectives includes: using the volute profile model equation as the constraint condition for the genetic algorithm, and setting the optimization objective of the genetic algorithm as... Where ψ represents the flow coefficient and η represents the efficiency. By setting the flow coefficient ψ and efficiency η as the optimization objectives of the genetic algorithm, it is ensured that the designed volute type 1 wind turbine provides optimal airflow delivery capacity while maintaining the highest operating efficiency. This means that under the same power input, the wind turbine can output a larger air volume and operate with lower energy consumption. Finding the optimal balance between flow coefficient and efficiency through the genetic algorithm avoids the situation where pursuing one performance indicator at the expense of the other, thereby maximizing the overall performance of the wind turbine.

[0071] It should be noted that the weight ratio of flow coefficient to efficiency in the optimization objective is 3.

[0072] Specifically, the equation for the volute-shaped line model is: The constraints also include in, The starting azimuth angle of the side of the circular arc segment 121 that is away from the spiral segment 122; The azimuth angle of the side of the circular arc segment 121 closest to the spiral segment 122; For the azimuth angle of the volute type 1 line The corresponding point's polar radius; R2 is the average radius of the outer contour of blade 2; t is the volute tongue clearance, t=t0*R2, 0.1≤t0≤0.2; α is the helix angle of helix segment 122; a, b, c, d are parameters describing the change of helix angle with azimuth angle; is the azimuth angle in polar coordinates; L is the preset width value.

[0073] Specifically, the method for determining the optimal volute profile using a genetic algorithm includes: determining the azimuth angle at the connection point of the circular arc segment and the helical segment, or the average radius of the circular arc segment, using the genetic algorithm. With this setup, determining the azimuth angle at the connection point of the circular arc segment and the helical segment, as well as the average radius of the circular arc segment, through the genetic algorithm enables precise optimization of the key parameters of the volute profile 1. These parameters directly affect the transition and diffusion of airflow within the volute 1, thereby affecting the total pressure and efficiency of the fan.

[0074] Specifically, the method for determining the optimal volute profile using a genetic algorithm includes: determining the parameters a, b, c, and d used to describe the variation of the helix angle with the azimuth angle using a genetic algorithm. In this way, by determining the parameters a, b, c, and d, the optimal shape of the helix segment 122 can be obtained, thereby reducing flow losses and improving the aerodynamic performance of the designed fan.

[0075] Specifically, the polar coordinate expression for the optimal volute profile is:

[0076] Specifically, the impeller parameters before and after optimization are compared in the table below:

[0077] It should be noted that the inlet diameter refers to the maximum diameter at the impeller inlet (i.e., the part where the airflow enters the impeller). The outlet diameter refers to the maximum diameter at the impeller outlet (i.e., the part where the airflow leaves the impeller). The inlet installation angle refers to the angle between the blades at the impeller inlet and the radial line. The outlet installation angle refers to the angle between the blades at the impeller outlet and the radial line.

[0078] As shown in Figure 2, the optimized volute profile 1 and blade outline of the fan differ significantly from the conventional design. The unoptimized volute 31 and blade 32 represent the traditional design. The optimized volute 1 and blade design, by introducing the optimal volute profile, effectively increases the impeller diameter, enhancing work capacity. Simultaneously, the optimized helix angle significantly reduces flow losses and improves efficiency. Furthermore, compared to the unoptimized conventional design, while improving aerodynamic performance, the overall dimensions have not increased significantly, maintaining a smaller overall size, thus improving the fan's working capacity within limited space.

[0079] Figure 3 shows a comparison of the total pressure-flow curves between the optimized fan and the conventional fan (the original design of the volute 31 and the original design of the blade 32 in Figure 2). The annular variable helix angle volute fan is the fan optimized using this scheme. During the flow rate variation from low to high, the total pressure of the optimized fan (triangle marker) is consistently higher than that of the conventional fan (dot marker), especially when the flow rate approaches 500 m³ / s. 3 At a pressure of / h, the optimized fan's total pressure advantage is more pronounced. This indicates that the optimized volute type 1 line design can significantly improve the fan's work capacity even under space-constrained conditions.

[0080] As shown in Figure 4, the color variations illustrate the entropy productivity distribution of the optimized fan and the conventional fan (the original design of the volute 31 and blade 32 in Figure 2) under the same operating conditions. In the optimized fan's flow field, the gradient from blue to red represents the change in entropy productivity from low to high. Compared to the conventional fan, the optimized fan generally exhibits lower entropy productivity in all regions of the flow field, indicating that the optimized design effectively reduces flow losses and improves the fan's energy efficiency.

[0081] As shown in Figure 5, the optimized fan further demonstrates its advantages in terms of total pressure coefficient, flow coefficient, and efficiency. Within the flow coefficient range of 0 to 0.30, the optimized fan (solid line) exhibits higher total pressure coefficient and efficiency than the conventional fan (dashed line), with the high-efficiency operating point shifting towards higher flow rates. Particularly when the flow coefficient approaches 0.25, the optimized fan not only boasts a higher total pressure coefficient but also a significantly improved efficiency.

[0082] As shown in Figure 6, Figure 6 illustrates the difference between the optimized volute profile and impeller outline of the wind turbine and the impeller outline of the conventional volute profile (including volute profiles using logarithmic spirals and Archimedean spirals). The optimized volute profile (red solid line) adopts a hybrid design of circular arc segments and spiral segments.

[0083] Specifically, assuming the same fan capacity, the dimensions of the logarithmic spiral volute profile (solid green line) and the Archimedean spiral volute profile (solid blue line) are larger than those of the optimized volute profile (solid red line). The diameter of the optimized volute impeller profile (solid black line) is larger than that of the conventional volute impeller profile (dashed black line). Therefore, fans using the optimized volute profile and impeller profile have stronger work capacity and are more suitable for applications in confined spaces.

[0084] Specifically, the impeller diameter and lateral dimensions of conventional and designed volute fans are compared in the table below:

[0085] As can be seen from the above description, the embodiments of this application achieve the following technical effects: the annular variable helix angle volute profile, composed of annular and variable helix angle sections connected in sequence, maintains a large impeller diameter while keeping aerodynamic performance at a high level, improving the fan capacity in confined spaces and providing a direction for the miniaturization of centrifugal fans; a theoretical model of the annular variable helix angle volute profile is established based on the volute profile design parameters, providing a basis for product design, improving fan design efficiency, and combining optimization algorithms to obtain the optimal volute profile design for a certain air supply terminal and construct a centrifugal fan, significantly improving its fan capacity.

[0086] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, or combinations thereof.

[0087] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0088] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0089] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0090] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0091] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A volute, characterized by, The volute has an air inlet and an air outlet; in the longitudinal section of the volute, the profile of the volute includes: Interconnected arc segments (121) and spiral segments (122), the corresponding parts of the arc segments (121) and the corresponding parts of the spiral segments (122) are used to form the fan cavity of the fan; the spiral segment (122) is located on the side of the arc segments (121) near the air outlet, the spiral segment (122) is smoothly connected to the arc segments (121) and extends toward the air outlet.

2. The volute of claim 1, wherein The profile of the volute also includes: The arc segment (123) is smoothly connected to the side of the circular arc segment (121) away from the spiral segment (122), and the arc segment (123) is a circular arc segment or a spiral segment.

3. The volute according to claim 2, characterized in that, The arc segment (123) is a circular arc segment, and the average radius of the arc segment (123) is greater than or equal to the average radius of the circular arc segment (121); wherein, the average radius of the arc segment (123) is the average of all position radii calculated along the circular arc segment from the starting point to the ending point; the average radius of the circular arc segment (121) is the average of all position radii calculated along the circular arc segment 121 from the starting point to the ending point.

4. The volute according to claim 2, characterized in that, The arc segment (123) is a circular arc segment. Along the circular arc segment from the starting point to the ending point, the ratio of the maximum value to the minimum value of all position radii is greater than or equal to 1 and less than or equal to 1.

1.

5. The volute of claim 2, wherein, The arc segment (123) is a spiral segment, which is a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral.

6. The volute of claim 1, wherein, The profile of the volute also includes: The first air outlet section (111) and the second air outlet section (112) are arranged opposite to each other to form the air outlet, and the connecting end of the second air outlet section (112) extends out of the connecting end of the first air outlet section (111). The first air outlet segment (111) is connected to the end of the arc segment (121) away from the spiral segment (122), and the second air outlet segment (112) is connected to the end of the spiral segment (122) away from the arc segment (121).

7. The volute according to claim 1, characterized in that, The starting azimuth angle where the circular arc segment (121) is located away from the side of the spiral segment (122) is or, The azimuth angle where the circular arc segment (121) is located near one side of the spiral segment (122) is or, Along the extending direction of the arc segment (121), the arc segment (121) has a plurality of sequentially connected arc segments, the maximum radius of each arc segment being R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min ;or, The starting azimuth angle where the circular arc segment (121) is located away from the side of the spiral segment (122) is The azimuth angle where the circular arc segment (121) is located near one side of the spiral segment (122) is or, The starting azimuth angle where the circular arc segment (121) is located away from the side of the spiral segment (122) is Along the extending direction of the arc segment (121), the arc segment (121) has a plurality of sequentially connected arc segments, the maximum radius of each arc segment being R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min ;or, The azimuth angle where the circular arc segment (121) is located near one side of the spiral segment (122) is Along the extending direction of the arc segment (121), the arc segment (121) has a plurality of sequentially connected arc segments, the maximum radius of each arc segment being R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min ;or, The starting azimuth angle where the circular arc segment (121) is located away from the side of the spiral segment (122) is The azimuth angle where the circular arc segment (121) is located near one side of the spiral segment (122) is Along the extending direction of the arc segment (121), the arc segment (121) has a plurality of sequentially connected arc segments, the maximum radius of each arc segment being R. max The minimum radius is R min ,0<(R) max -R min ) / R min ≤0.1; or, R max =R min .

8. The volute of claim 1, wherein, The spiral segment (122) is a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral.

9. The volute of claim 1, wherein, Along the extension direction from the arc segment (121) to the air outlet, the spiral segment (122) is a variable-angle spiral with a gradually expanding spiral angle.

10. The volute of claim 9, wherein, The polar coordinate expression of the spiral segment (122) is wherein, is a terminal azimuth angle at which the circular arc segment (121) and the spiral segment (122) are connected, a is a spiral angle of the spiral segment (122), a, b, c, d are parameters introduced to describe the change of the spiral angle with the azimuth angle, is the azimuth angle of the polar coordinate.

11. The volute of claim 10, wherein, L is a preset width value, is an azimuth angle is a polar radius of a point on the profile line of the corresponding volute.

12. A fan, comprising: include: The volute according to any one of claims 1 to 11.

13. The fan of claim 12, wherein, The fan also includes a fan blade (2), which is disposed inside the fan cavity. The periphery of the fan blade (2) is disposed opposite to the arc segment (121). The average radius of the arc segment (121) is R1, and the average radius of the outer contour of the fan blade (2) is R2. R1 = R2 + t, t = t0 * R2, 0.1 ≤ t0 ≤ 0.

2.

14. A domestic appliance characterized in that, include: The fan according to any one of claims 12 to 13, wherein the household appliance is any one of an air conditioner, an air purifier, and a range hood.

15. A method of designing a fan volute profile, characterized by, The design method is applicable to the volute casing according to any one of claims 1 to 11; the design method includes: The profile of the volute includes circular arc segments and helical segments; Determine the polar coordinate equations corresponding to the circular arc segment and the spiral segment respectively to obtain the volute profile model equation; Based on the aforementioned volute profile model equation, with flow coefficient and efficiency as optimization objectives, the optimal volute profile is determined using a genetic algorithm.

16. The design method according to claim 15, characterized in that, The method according to the volute model equation, taking the flow coefficient and the efficiency as the optimization target, comprises: taking the volute model equation as the constraint condition of the genetic algorithm, and setting the optimization target of the genetic algorithm as Where ψ is the flow coefficient and η is the efficiency; or... The step of determining the optimal volute profile using a genetic algorithm includes: determining, via a genetic algorithm, the azimuth angle at the junction of the circular arc segment and the helical segment, or the average radius of the circular arc segment; or... The method according to the volute model equation, taking the flow coefficient and the efficiency as the optimization target, comprises: taking the volute model equation as the constraint condition of the genetic algorithm, and setting the optimization target of the genetic algorithm as The step of determining the optimal volute profile using a genetic algorithm includes: determining the azimuth angle at the connection point of the circular arc segment and the spiral segment, or the average radius of the circular arc segment, using a genetic algorithm.

17. The design method according to claim 16, characterized in that, The volute profile model equation is The constraint conditions further include wherein, the starting azimuth at which the side of the circular arc segment 121 distanced from the helical segment 122 lies; the azimuth in which the side of the circular arc segment 121 close to the helical segment 122 is located; For spiral case 1 profile azimuth angle R2 is the average radius of the outer profile of the blade 2; t is the tip clearance, t = t0*R2, 0.1 < t0 < 0.2; a, b, c, d are parameters introduced to describe the variation of the helix angle with the azimuthal angle; is the azimuth angle in polar coordinates; L is the preset width value.

18. The method of claim 16, wherein: The polar coordinate expression of the optimal volute profile is:

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