Volute, fan, household appliance and design method

Abstract

The invention provides a volute, a fan, a household appliance and a design method. The volute is provided with an air inlet and an air outlet; on the longitudinal section of the volute, the molded line of the volute comprises an arc subsection and a spiral subsection which are connected with each other, and the part corresponding to the arc subsection and the part corresponding to the spiral subsection are both used for defining a fan cavity of the fan. The spiral section is located on the side, close to the air outlet, of the arc section, and the spiral section is smoothly connected with the arc section and extends in the direction of the air outlet. By means of the technical scheme, the technical problem that in the prior art, the aerodynamic performance of a fan is insufficient can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and in particular, to a volute, a fan, a household appliance, and a design method. Background Art

[0002] Currently, in household appliances such as air conditioners, air purifiers, and range hoods, multi-wing centrifugal fans are widely used due to their characteristics of high total pressure and low noise. However, the internal space of these appliances is limited. In addition to the fan, other key components also need to be accommodated, resulting in strict restrictions on the fan design space.

[0003] However, in the design of traditional centrifugal fans, the profile of the volute mostly adopts logarithmic spiral or Archimedean spiral. Although these profile designs meet the basic functional requirements of the fan to a certain extent, their performance in a limited space is insufficient. The optimization of the volute profile, especially its matching with the impeller, is the key to fan design. Under the condition of limited space, traditional volute profiles often cannot make full use of the available space, resulting in limited impeller diameter, which affects the work capacity of the fan, and further affects the aerodynamic performance of the fan, reducing the total pressure and efficiency of the fan. Summary of the Invention

[0004] The main purpose of the present invention is to provide a volute, a fan, a household appliance, and a design method to solve the technical problem of insufficient aerodynamic performance of the fan in the prior art.

[0005] To achieve the above object, according to one aspect of the present invention, a volute is provided; the volute has an air inlet and an air outlet; in the longitudinal section of the volute, the profile of the volute includes:

[0006] Connected arc segments and spiral segments, the parts corresponding to the arc segments and the parts corresponding to the spiral segments are both used to enclose the fan cavity of the fan; the spiral segments are located on the side of the arc segments close to the air outlet, and the spiral segments are smoothly connected to the arc segments and extend in the direction of the air outlet.

[0007] Furthermore, the profile of the volute further includes:

[0008] An arc section, the arc section is smoothly connected to the side of the arc segment away from the spiral segment, and the arc section is an arc line segment or a spiral line segment.

[0009] Furthermore, the profile of the volute further includes:

[0010] Relatively arranged first air outlet segments and second air outlet segments, the first air outlet segments and the second air outlet segments are spaced apart from each other to form an air outlet, and the connecting end of the second air outlet segment extends beyond the connecting end of the first air outlet segment;

[0011] Among them, the connecting end of the first air outlet segment is connected to one end of the arc segment far from the spiral segment, and the connecting end of the second air outlet segment is connected to one end of the spiral segment far from the arc segment.

[0012] Further, the starting azimuth angle where the side of the arc segment far from the spiral segment is located is and / or,

[0013] The azimuth angle where the side of the arc segment close to the spiral segment is located is and / or,

[0014] Along the extending direction of the arc segment, the arc segment has a plurality of sequentially connected arc segments, and the maximum radius of each arc segment is R max and the minimum radius is R min , 0 < (R max -R min ) / R min ≤ 0.1; or, R max = R min .

[0015] Further, the spiral segment is a logarithmic spiral or an Archimedean spiral or a variable angle spiral.

[0016] Further, along the extending direction from the arc segment to the air outlet of the fan, the spiral segment is a variable angle spiral with an increasing spiral angle.

[0017] Further, the polar coordinate expression of the spiral segment is Among them, is the termination azimuth angle where the connection of the arc segment and the spiral segment is located, α is the spiral angle of the spiral segment, 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.

[0018] Further, L is a preset width value, is the polar radius of the point on the volute profile corresponding to the azimuth angle .

[0019] According to another aspect of the present invention, a fan is provided, including: the volute provided above.

[0020] Further, the fan further includes a wind blade, the wind blade is arranged in the fan cavity, the periphery of the wind blade is arranged opposite to the arc segment, the average radius of the arc segment is R1, the average radius of the outer contour of the wind blade is R2, R1 = R2 + t, t = t0 * R2, 0.1 ≤ t0 ≤ 0.2.

[0021] According to another aspect of the present invention, there is provided a household appliance, including: the blower provided above, and the household appliance is any one of an air conditioner, an air purifier, and a range hood.

[0022] According to still another aspect of the present invention, there is provided a design method for the blower volute profile, which is applicable to the volute provided above; the design method includes:

[0023] Making the profile of the volute include an arc segment and a spiral segment;

[0024] Determining the polar coordinate equations corresponding to the arc segment and the spiral segment respectively to obtain the volute profile model equation;

[0025] According to the volute profile model equation, taking the flow coefficient and efficiency as the optimization objectives, determining the optimal volute profile through the genetic algorithm.

[0026] Further, according to the volute profile model equation, taking the flow coefficient and efficiency as the optimization objectives, includes: taking the volute profile model equation as the constraint condition of the genetic algorithm, and setting the optimization objective of the genetic algorithm as where ψ is the flow coefficient and η is the efficiency; and / or,

[0027] Determining the optimal volute profile through the genetic algorithm includes: determining the azimuth angle at the connection of the arc segment and the spiral segment and / or the average radius of the arc segment through the genetic algorithm.

[0028] Applying the technical solution of the present invention, through the volute profile design combining the arc segment and the spiral segment, the aerodynamic performance of the blower can be significantly improved. The use of the arc segment enables the impeller of the blower to have a larger diameter, thereby enhancing the work capacity of the blower. In addition, the smooth connection of the arc segment to the spiral segment ensures the flow continuity and stability of the air flow when transitioning from the arc segment to the spiral segment, reduces the flow loss, and improves the total pressure and efficiency of the blower. Secondly, the spiral segment further optimizes the diffusion and mixing process of the air flow in the volute. This can not only improve the total pressure coefficient of the blower at high flow rates, but also reduce the entropy production rate, that is, the internal flow loss, in the entire system, thereby improving the blower efficiency and achieving a double increase in the air volume and total pressure under the same spatial dimensions. Through such a setting, even when the size of the blower is small, the aerodynamic performance of the blower can be ensured, enabling the blower to achieve an air volume level that matches or even exceeds that of a conventional volute blower under a smaller lateral dimension, providing a direction for the miniaturization of centrifugal blowers. Therefore, through the technical solution of the present invention, the technical problem of insufficient aerodynamic performance of the blower in the prior art can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 shows a schematic structural diagram of the volute profile and the outer contour of the wind blade provided in the first embodiment of the present invention;

[0031] Figure 2 shows a comparative schematic diagram of the volute profile and the outer contour of the wind blade of the volute provided in the first embodiment of the present invention and those of a conventional fan;

[0032] Figure 3 shows a comparative schematic diagram of the p-q (total pressure - flow rate) curves of the fan provided in the second embodiment of the present invention and a conventional fan;

[0033] Figure 4 shows a comparative schematic diagram of the distribution of the flow field entropy production rate of the fan provided in the second embodiment of the present invention and a conventional fan;

[0034] Figure 5 shows a comparative schematic diagram of the total pressure coefficient - flow coefficient - efficiency characteristic curves of the fan provided in the second embodiment of the present invention and a conventional fan;

[0035] Figure 6 shows a comparative schematic diagram of the volute profiles of the fan provided in the second embodiment of the present invention and a conventional fan at the same fan capacity level.

[0036] Among them, the above-mentioned drawings include the following reference numerals:

[0037] 1, volute;

[0038] 11, air outlet section; 111, first air outlet sub-section; 112, second air outlet sub-section; 113, third air outlet sub-section;

[0039] 12, air guiding section; 121, arc sub-section; 122, spiral sub-section; 123, arc section;

[0040] 2, wind blade;

[0041] 31, volute before optimization;

[0042] 32, wind blade before optimization. Detailed implementation manners

[0043] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0044] As Figures 1 to 6As shown in the figure, Embodiment 1 of the present invention provides a volute 1, which has an air inlet and an air outlet; in the longitudinal section of the volute 1, the profile line of the volute 1 includes an arc segment 121 and a spiral segment 122 that are connected to each other. The parts corresponding to the arc segment 121 and the parts corresponding to the spiral segment 122 are both used to enclose the fan cavity 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 in the direction of the air outlet.

[0045] By using the volute 1 provided in Embodiment 1 of the present invention and adopting the volute 1 profile line design that combines the arc segment 121 and the spiral segment 122, the aerodynamic performance of the fan can be significantly improved. The use of the arc segment 121 enables the impeller of the fan blade 2 of the fan to have a larger diameter, thereby enhancing the work capacity of the fan. In addition, the smooth connection of the arc segment 121 to the spiral segment 122 ensures the flow continuity and stability of the air flow when transitioning from the arc segment 121 to the spiral segment 122, reduces the flow loss, and improves the total pressure and efficiency of the fan. Secondly, the spiral segment 122 further optimizes the diffusion and mixing process of the air flow in the volute 1. This can not only improve the total pressure coefficient of the fan at high flow rates, but also reduce the entropy production rate within the entire system, that is, the internal flow loss, thereby improving the fan efficiency and achieving a double increase in the air volume and total pressure under the same spatial dimensions. Through such a setting, even when the fan size is small, the aerodynamic performance of the fan can be ensured, enabling the fan to achieve an air volume level that matches or even exceeds that of a conventional volute fan with a smaller lateral dimension, providing a direction for the miniaturization of centrifugal fans. Therefore, through the volute provided in this embodiment, the technical problem of insufficient aerodynamic performance of the fan in the prior art can be solved.

[0046] It should be noted that the longitudinal section of the volute 1 refers to the sectional view formed by vertically cutting along the direction of the fan central axis through the geometric center of the volute 1, specifically as Figure 1 shown. Figure 1 The longitudinal sectional view of shows the profile line of the volute 1 and the outer contour line of the fan blade 2.

[0047] Specifically, the profile line of the volute 1 includes an air outlet section 11 and a guide air section 12. The air outlet section 11 includes a first air outlet segment 111, a third air outlet segment 113, and a second air outlet segment 112 that are connected in sequence. The part of the air outlet section 11 corresponding to the fan encloses the air outlet of the fan. The guide air 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 jointly enclose the fan cavity of the fan, and the fan blade 2 is located in the fan cavity. Figure 1The longitudinal sectional view shows the shapes and connection modes of the arc segment 121 and the spiral segment 122, as well as important design parameters such as the relationship between the volute opening degree A, the impeller diameter R2 of the airfoil 2, and the radius R1 of the arc segment 121. The volute opening degree A refers to the difference between the width of the volute outlet and the width of the narrowest part of the volute (usually the volute wall near the impeller inlet).

[0048] Specifically, the profile line of the volute 1 further includes an arc segment 123, which is smoothly connected to the side of the arc segment 121 away from the spiral segment 122. The arc segment 123 is an arc line segment or a spiral line segment. With such a structural arrangement, the arc segment 123 is designed to optimize the flow efficiency of the air flow in the volute 1. Whether an arc line segment or a spiral line segment is used as the arc segment 123, the profile line of the volute 1 can be adjusted according to the actual working conditions and requirements of the fan to achieve better aerodynamic performance. The arc line segment can provide more stable fluid inlet conditions, enabling a larger diameter for accommodating the impeller, while the spiral line segment can better match the spiral characteristics of the spiral segment 122. The optimal selection of the two can further improve the total pressure and efficiency of the fan.

[0049] Specifically, when the arc segment 123 is an arc line segment, the average radius of the arc segment 123 is greater than or equal to the average radius of the arc segment 121. In this way, the volute 1 can provide a larger diameter space for the impeller, thereby enhancing the work capacity of the impeller and increasing the overall air volume and total pressure of the fan.

[0050] It should be noted that the average radius of the arc segment 123 refers to the average value of the radii at all positions along this arc line segment from the starting point to the ending point. The average radius of the arc segment 121 refers to the average value of the radii at all positions along this arc segment 121 from the starting point to the ending point.

[0051] It should be noted that when the arc segment 123 is an arc line segment, the ratio of the maximum value to the minimum value of the radii at all positions along this arc line segment from the starting point to the ending point is greater than or equal to 1 and less than or equal to 1.1.

[0052] Specifically, when the arc segment 123 is a spiral line segment, the arc segment 123 is a logarithmic spiral, an Archimedean spiral, or a variable-angle spiral. In this way, it can effectively improve the diffusion characteristics of the air flow in the volute 1, reduce the flow loss, and improve the total pressure and efficiency of the fan.

[0053] Specifically, the profile line of the volute 1 further includes a first air outlet segment 111 and a second air outlet segment 112 which are oppositely arranged. The first air outlet segment 111 and the second air outlet segment 112 are spaced apart from each other to form an air outlet, and the connecting end of the second air outlet segment 112 extends beyond the connecting end of the first air outlet segment 111. Among them, the connecting end of the first air outlet segment 111 is connected to one end of the arc segment 121 far from the spiral segment 122, and the connecting end of the second air outlet segment 112 is connected to one end of the spiral segment 122 far from the arc segment 121. With such a structural arrangement, the arc segment 121 is arranged at the starting position of the air guiding section 12 of the profile line of the volute 1 (equivalent to the starting part of the flow channel of the fan cavity, that is, the side of the flow channel close to the air inlet). The flow velocity of this part of the starting flow channel is relatively low. Arranging the arc segment 121 in this part to increase the diameter of the impeller can make the gas flow loss in the fan cavity smaller and maximize the air volume.

[0054] Specifically, the starting azimuth angle of the side of the arc segment 121 far from the spiral segment 122 is With such a structural arrangement, it can better cooperate with the air outlet section 11, ensure enough space to accommodate a larger impeller diameter, thereby improving the work capacity of the impeller and enhancing the air volume and total pressure of the fan.

[0055] Specifically, the azimuth angle of the side of the arc segment 121 close to the spiral segment 122 is With such a structural arrangement, since the proportion of the arc segment 121 is larger, the larger the impeller diameter that can be accommodated, and the stronger the work capacity of the impeller. However, the proportion of the later-stage spiral segment 122 for pressure expansion decreases, which will lead to an increase in flow loss, making the output fan capacity not necessarily enhanced. When the proportion of the arc segment 121 is relatively small, the increase in the work capacity of the impeller is greater than the increased flow loss, and the fan capacity is improved. But when the proportion of the arc segment 121 further increases, the internal flow field of the fan will deteriorate sharply. In the most extreme case, the aerodynamic performance of a pure annular volute centrifugal fan with the same fan size is significantly lower than that of a conventional volute fan. Therefore, the output capacity of the fan will show a trend of first rising and then falling with the increase of the impeller diameter, which indicates that there is an optimal impeller diameter, that is, an optimal value. Setting the value of this azimuth angle within [135°, 225°] can better balance the work capacity of the impeller and the flow loss, so that the fan has better aerodynamic performance.

[0056] It should be noted that the above starting azimuth angle and azimuth angle are both based on Figure 1 the polar coordinate axis in. The origin of this polar coordinate axis is at the center of the cross-section of the wind blade 2 of the fan to which the volute 1 belongs. The wind blade 2 is arranged in the fan cavity of the fan. The polar axis extends horizontally.

[0057] Specifically, along the extension direction of the arc segment 121, the arc segment 121 has a plurality of sequentially connected arc sections, and the maximum radius of each arc section is R max and the minimum radius is R min , 0 < (R max - R min ) / R min ≤ 0.1; or, R max = R min . With such a structural setting, the arc segment 121 is a perfect circle (the case where R max = R min corresponds) or an arc part approximately in the shape of a perfect circle (the case where 0 < (R max - R min ) / R min ≤ 0.1 corresponds), so that sufficient space can be guaranteed to accommodate a larger impeller diameter, thereby improving the work capacity of the impeller, optimizing the matching between the impeller and the volute 1, and achieving higher aerodynamic efficiency.

[0058] Specifically, the spiral segment 122 is a logarithmic spiral or an Archimedean spiral or a variable - angle spiral. With such a structural setting, the diffuser of the gas flow path in the fan cavity can be carried out through the setting of the spiral segment 122, the flow field in the fan cavity can be optimized, the flow loss of the gas can be reduced, and the aerodynamic performance of the fan can be improved.

[0059] In this embodiment, along the extension direction from the arc segment 121 to the air outlet of the fan, the spiral segment 122 is a variable - angle spiral with an increasing spiral angle. In this way, the spiral design of the conventional volute 1 is either based on the equal - circulation assumption (logarithmic spiral) or based on the equal - velocity distribution assumption (Archimedean spiral), both of which are based on the one - dimensional ideal steady flow, and it is assumed that the air flow is uniformly mixed after rapid diffusion in the volute 1. The actual gas is a non - ideal gas and belongs to the flow in three - dimensional space, and its flow situation is complex, and the mixing degree of the air flow in the flow path is not necessarily uniform. Therefore, using a spiral with a changing spiral angle can further reduce the flow loss of the air flow and conform to the actual working conditions of the fan.

[0060] Specifically, the polar - coordinate expression of the spiral segment 122 is where is the termination azimuth angle where the arc segment 121 and the spiral segment 122 are connected, α is the spiral angle of the spiral segment 122, and a, b, c, d are parameters introduced to describe the change of the spiral angle with the azimuth angle, is the azimuth angle in polar coordinates. In this way, by constructing the polar coordinate expression of the spiral segment 122, the shape of the variable-angle spiral can be accurately described, which is convenient for realizing the optimal design of the volute 1 profile line, thereby effectively reducing the flow loss of the air flow in the volute 1 and improving the total pressure and efficiency of the fan.

[0061] It should be noted that the spiral angle α of the spiral segment 122 is the angle between the tangent line of the point on the spiral segment 122 and the perpendicular line of the polar radius line corresponding to the point, as specifically shown in Figure 1 the figure.

[0062] Specifically, L is a preset width value, is the azimuth angle and is the polar radius of the point on the volute 1 profile line corresponding to. Such a structural setting is to take into account that the actual installation environment of the fan is a limited space and the installation space size is limited. By limiting the preset width value, it is helpful to determine the shape of the optimal air guiding section 12 in the limited space, thereby meeting the actual production requirements.

[0063] Embodiment 2 of the present invention provides a fan, and the fan includes the volute provided in Embodiment 1.

[0064] By using the fan provided in Embodiment 2 of the present invention, the total pressure of the fan can be increased through the design of the profile line of the volute 1 of the fan, the internal flow loss can also be reduced, and the efficiency of the fan can be improved. For household appliances, this means that while providing the same or better performance, energy consumption can be reduced, operating costs can be lowered, and the overall energy efficiency can be improved. It also means that higher air volume and total pressure can be achieved in the same or smaller equipment space. By using the fan provided in Embodiment 1, the fan can be made more compact as a whole while maintaining high performance. This is particularly important for a household environment with limited space, making the design of household appliances more space-saving, convenient for installation and maintenance, and improving the convenience of user use. Therefore, through the fan provided in this embodiment, the technical problem of insufficient aerodynamic performance of the fan in the prior art can be solved.

[0065] Specifically, the fan is a centrifugal fan.

[0066] In this embodiment, the fan further includes a wind blade 2 disposed in the fan cavity. The periphery of the wind blade 2 is disposed opposite to the arc segment 121. The average radius of the arc segment 121 is R1, the average radius of the outer contour of the wind blade 2 is R2, and R1 = R2 + t, where t = t0 * R2 and 0.1 ≤ t0 ≤ 0.2. With such a structural arrangement, by setting the distance t between the wind 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 wind blade 2 and the volute 1 is neither too large to cause air leakage nor too small to cause an increase in air flow resistance, thereby achieving efficient transmission of air flow between the volute 1 and the wind blade 2. The implementation effect shows that when the fan is operating, the transmission efficiency of the air flow between the volute 1 and the wind blade 2 is significantly improved. Due to the reasonable setting of the gap t, the air flow transmission efficiency is high, reducing leakage and resistance, thereby improving the total pressure and efficiency of the fan. In addition, through such a setting, it is also convenient to change the diameter of the outer contour of the accommodated wind blade 2 by adjusting the average radius of the arc segment 121, thereby enhancing the work capacity of the impeller and improving the aerodynamic performance of the fan.

[0067] It should be noted that the average radius of the arc segment 121 refers to the average value of the radii at all positions calculated along the arc segment 121 from the starting point to the ending point. The average radius of the circumference of the wind blade 2 refers to the average value of the radii at all positions calculated along the outer contour of the impeller from the starting point to the ending point.

[0068] Embodiment 3 of the present invention provides a household appliance, which includes the fan provided in Embodiment 2, and the household appliance is any one of an air conditioner, an air purifier, and a range hood.

[0069] By using the household appliance provided in Embodiment 3 of the present invention, the total pressure of the fan can be increased through the design of the profile of the fan volute 1, and the internal flow loss can also be reduced, improving the efficiency of the fan. For household appliances, this means that while providing the same or better performance, energy consumption can be reduced, operating costs can be lowered, and the overall energy efficiency can be improved. It also means that higher air volume and total pressure can be achieved in the same or smaller equipment space. By using the fan provided in Embodiment 1, the fan can maintain high performance while making the overall equipment more compact. This is particularly important for home environments with limited space, making the design of home appliances more space-saving, facilitating installation and maintenance, and improving the convenience of user use. Therefore, through the household appliance provided in this embodiment, the technical problem of insufficient aerodynamic performance of the fan in the prior art can be solved.

[0070] Embodiment 4 of the present invention provides a design method for the volute profile of a fan, which is applicable to the volute provided in Embodiment 1; the design method includes: making the profile of the volute 1 include an arc segment 121 and a spiral segment 122; determining the polar coordinate equations corresponding to the arc segment 121 and the spiral segment 122 respectively to obtain the volute profile model equation; and determining the optimal volute profile through a genetic algorithm with the flow coefficient and efficiency as the optimization objectives.

[0071] By using the design method for the volute profile of a fan provided in Embodiment 4 of the present invention, the concepts of the arc segment 121 and the spiral segment 122 can be introduced, and the shapes of these two segments can be accurately described by polar coordinate equations, which can more accurately reflect the actual flow characteristics of the air flow inside the volute 1. With the help of the genetic algorithm, taking the flow coefficient and efficiency as the optimization objectives, it can help achieve the best matching between the volute 1 and the impeller in a limited space, enabling the fan to achieve miniaturized design while maintaining high performance. For the design of the traditional variable-angle spiral line, the starting spiral angle and the ending spiral angle need to be given, and then interpolation is performed at 0.5π, π, and 1.5π according to empirical formulas, and then the complete variable-angle spiral line is obtained by cubic polynomial fitting. However, by using the genetic algorithm, the optimal solution can be quickly screened out from a large number of possible design schemes, greatly shortening the R & D cycle and reducing the R & D cost. This method avoids the resource waste that may be caused by the traditional trial-and-error method and improves the design efficiency. And compared with the traditional design method, the designed profile is more in line with the actual air flow, and the air flow loss is smaller. Therefore, through the design method for the volute profile of a fan provided in this embodiment, the technical problem of insufficient aerodynamic performance of the existing fans can be solved.

[0072] It should be noted that the genetic algorithm is the NSGA-II algorithm (Non-dominated Sorting Genetic Algorithm II). The steps adopted by the genetic algorithm are the same as those of the conventional NSGA-II algorithm, except for different optimization objectives and constraint conditions.

[0073] Specifically, the method of taking the flow coefficient and efficiency as the optimization objectives according to the volute profile model equation includes: using the volute profile model equation as the constraint condition of the genetic algorithm, and setting the optimization objective of the genetic algorithm as where ψ is the flow coefficient and η is the efficiency. With such a setting, setting the flow coefficient ψ and the efficiency η as the optimization objectives of the genetic algorithm can ensure that the designed profile of the volute 1 can provide the best air flow conveying capacity while maintaining the highest operating efficiency. This means that under the same power input, the fan can output a larger air volume and operate with lower energy consumption. By using the genetic algorithm to find the best balance point between the flow coefficient and the efficiency, the situation of sacrificing one performance index for the other can be avoided, thus maximizing the comprehensive performance of the fan.

[0074] It should be noted that the weight ratio of the flow coefficient to the efficiency in the optimization objective is 3.

[0075] Specifically, the volute profile model equation is The constraint conditions also include Among them, is the starting azimuth angle on the side of the arc segment 121 far from the spiral segment 122; is the azimuth angle on the side of the arc segment 121 close to the spiral segment 122; is the azimuth angle on the volute 1 profile The corresponding polar radius of the point; R2 is the average radius of the outer contour of the wind blade 2; t is the volute tongue clearance, t = t0 * R2, 0.1 ≤ t0 ≤ 0.2; α is the spiral angle of the spiral segment 122; a, b, c, d are parameters introduced to describe the variation of the spiral angle with the azimuth angle; is the azimuth angle of the polar coordinate; L is the preset width value.

[0076] Specifically, the method for determining the optimal volute profile by the genetic algorithm includes: determining the azimuth angle at the connection of the arc segment and the spiral segment and / or the average radius of the arc segment by the genetic algorithm. With such a setting, by determining the azimuth angle at the connection of the arc segment and the spiral segment and the average radius of the arc segment by the genetic algorithm, precise optimization of the key parameters of the volute 1 profile can be achieved. These parameters directly affect the transition and diffusion of the air flow in the volute 1, thereby affecting the total pressure and efficiency of the fan.

[0077] Specifically, the method for determining the optimal volute profile by the genetic algorithm includes: determining the parameters a, b, c, d introduced to describe the variation of the spiral angle with the azimuth angle by the genetic algorithm. In this way, by determining the a, b, c, d parameters, the optimal shape of the spiral segment 122 can be obtained, thereby reducing the flow loss and improving the aerodynamic performance of the designed fan.

[0078] Specifically, the polar coordinate expression of the optimal volute profile is:

[0079]

[0080] Specifically, the comparison of the impeller parameters before and after optimization is shown in the following table:

[0081]

[0082] It should be noted that the inlet diameter refers to the maximum diameter at the impeller inlet (i.e., the part where the air flow enters the impeller). The outlet diameter is the maximum diameter at the impeller outlet (i.e., the part where the air flow leaves the impeller). The inlet installation angle is the angle between the blade and the radial line at the impeller inlet. The outlet installation angle is the angle between the blade and the radial line at the impeller outlet.

[0083] As shown Figure 2 in the figure Figure 2 , it shows the significant differences between the optimized Type 1 line of the fan volute (the best volute line) and the outer contour of the fan blade and the conventional design. The volute 31 before optimization and the fan blade 32 before optimization represent the traditional design. By introducing the best volute line, the optimized volute 1 and fan blade design effectively increase the impeller diameter, enhance the work capacity, and at the same time, the optimized design of the spiral angle significantly reduces the flow loss and improves the efficiency. And compared with the conventional design before optimization, on the premise of improving the aerodynamic performance, there is no significant increase in the external dimensions, maintaining a small external dimension, so as to improve the working ability of the fan in a limited space.

[0084] As Figure 3 shown Figure 3 in the figure Figure 2 , it shows a schematic diagram of the comparison of the total pressure-flow curves between the optimized fan and the conventional fan ( 3 the design form of the volute 31 before optimization and the fan blade 32 before optimization in Figure 2 ). The annular variable spiral angle volute fan is the fan optimized by this scheme. During the process of the flow rate changing from low to high, the total pressure of the optimized fan (triangle mark) is always higher than that of the conventional fan (dot mark), especially when the flow rate is close to 500 m 3 / h, the total pressure advantage of the optimized fan is more obvious. This shows that by adopting the optimized Type 1 line design of the volute, even under space limitation conditions, the work capacity of the fan can be significantly improved.

[0085] As Figure 4 shown Figure 4 in the figure Figure 2 , through the change of color depth, it shows the entropy production rate distribution of the flow field of the optimized fan and the conventional fan ( Figure 2 the design form of the volute 31 before optimization and the fan blade 32 before optimization in Figure 2 ) under the same working conditions. In the flow field of the optimized fan, the gradual change from blue to red represents the change of the entropy production rate from low to high. Compared with the conventional fan, the entropy production rate of the optimized fan is generally lower in each region of the flow field, which indicates that the optimized design effectively reduces the flow loss and improves the energy efficiency of the fan.

[0086] As Figure 5 shown Figure 5 in the figure

[0087] further shows the advantages of the optimized fan in terms of total pressure coefficient, flow coefficient and efficiency. In the range of flow coefficient from 0 to 0.30, both the total pressure coefficient and efficiency of the optimized fan (solid line) are higher than those of the conventional fan (dashed line), and the high-efficiency operating point shifts towards the large flow rate direction. Especially when the flow coefficient is close to 0.25, the optimized fan not only has a higher total pressure coefficient, but also the efficiency is significantly improved.

[0087] As Figure 6 shown Figure 6The figure shows the differences between the optimized blower volute profile and impeller outline and those of the conventional volute profile (including the volute profile with logarithmic spiral and the volute profile with Archimedean spiral). The optimized volute profile (red solid line) adopts a hybrid design of circular arc segments and spiral segments.

[0088] Specifically, on the premise of the same blower capacity level, the external dimensions of the logarithmic spiral volute profile (green solid line) and the Archimedean spiral volute profile (blue solid line) are larger than those of the optimized volute profile (red solid line). The diameter of the optimized blower impeller outline (black solid line) is larger than that of the conventional blower impeller outline (black dashed line). It can be seen that the blower applying the optimized blower volute profile and impeller outline has stronger work capacity and is more suitable for application in small spaces.

[0089] Specifically, the comparison of the impeller diameter and the blower transverse dimension between the conventional volute blower and the designed volute blower is shown in the following table:

[0090]

[0091] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: adopting an annular variable spiral angle volute profile composed of an annular part and a variable spiral angle part in sequence, so that while maintaining a relatively large impeller diameter, the aerodynamic performance is also maintained at a relatively high level, improving the blower capacity in a limited space and providing a direction for the miniaturization of centrifugal blowers; establishing a theoretical model of the annular variable spiral angle volute profile according to the volute profile design parameters, providing a basis for product design, improving the blower design efficiency, and combining with an optimization algorithm to obtain the best volute profile design for a certain air supply end and constituting a centrifugal blower, greatly improving its blower capacity.

[0092] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0093] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the description. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0094] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. are generally based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0095] For ease of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationships of one device or feature to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0096] In addition, it should be noted that the use of terms such as "first", "second", etc. to define components is only for the convenience of distinguishing the corresponding components. Without further statement, the above terms have no special meanings. Therefore, they should not be construed as limiting the scope of protection of the present application.

[0097] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A volute, characterized in that: The volute (1) has an air inlet and an air outlet; in the longitudinal section of the volute (1), the profile of the volute (1) includes: The circular arc segment (121) and the spiral segment (122) are connected to each other, and the corresponding part of the circular arc segment (121) and the corresponding part of the spiral segment (122) are both used to enclose a fan chamber of the fan; the spiral segment (122) is located on a side of the circular arc segment (121) close to the air outlet, and the spiral segment (122) is smoothly connected to the circular arc segment (121) and extends in the direction of the air outlet.

2. The volute according to claim 1, characterized in that: The profile of the volute (1) further includes: An arc segment (123), wherein the arc segment (123) is smoothly connected to a 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 1, characterized in that: The profile of the volute (1) further includes: A first air outlet segment (111) and a second air outlet segment (112) are arranged opposite to each other, the first air outlet segment (111) and the second air outlet segment (112) are spaced apart from each other to form the air outlet, and a connection end of the second air outlet segment (112) extends out from a connection end of the first air outlet segment (111); The connection end of the first air outlet segment (111) is connected to an end of the circular arc segment (121) away from the spiral segment (122), and the connection end of the second air outlet segment (112) is connected to an end of the spiral segment (122) away from the circular arc segment (121).

4. The volute according to claim 1, characterized in that: The starting azimuth angle of the side of the arc segment (121) away from the spiral segment (122) is and / or, The azimuth angle of the side of the arc segment (121) close to the spiral segment (122) is and / or, Along the extension direction of the circular arc segment (121), the circular arc segment (121) has a plurality of arc segments connected in sequence, 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 .

5. The volute according to claim 1, characterized in that: The spiral segment (122) is a logarithmic spiral, an Archimedean spiral, or a variable angle spiral.

6. The volute according to claim 1, characterized in that: Along the extension direction from the circular arc segment (121) to the air outlet, the spiral segment (122) is a variable-angle spiral line with a gradually increasing spiral angle.

7. The volute according to claim 6, characterized in that: The polar coordinate expression of the spiral segment (122) is: in, is the terminal azimuth angle of the connection between the arc segment (121) and the spiral segment (122), α is the 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 in polar coordinates.

8. The volute according to claim 7, characterized in that: L is the preset width value, Azimuth The polar radius of the corresponding point on the profile of the volute (1).

9. A fan, characterized in that: include: The volute according to any one of claims 1 to 8.

10. The fan according to claim 9, characterized in that: The fan further comprises a fan blade (2), wherein the fan blade (2) is arranged in the fan cavity, the periphery of the fan blade (2) is arranged opposite to the circular arc segment (121), the average radius of the circular arc segment (121) is R1, 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.

11. A household appliance, characterized in that: include: The fan according to any one of claims 9 to 10, wherein the household appliance is any one of an air conditioner, an air purifier, and a range hood.

12. A method for designing a fan volute profile, characterized in that: Applicable to the volute according to any one of claims 1 to 8; the design method comprises: The profile of the volute includes arc segments and spiral segments; Determine polar coordinate equations corresponding to the arc segment and the spiral segment respectively to obtain a volute profile model equation; According to the volute profile model equation, the optimal volute profile is determined by a genetic algorithm with flow coefficient and efficiency as optimization targets.

13. The design method according to claim 12, characterized in that: The method of optimizing the flow coefficient and efficiency according to the volute profile model equation includes: using the volute profile model equation as a constraint condition of the genetic algorithm, setting the optimization target of the genetic algorithm to Where ψ is the flow coefficient and η is the efficiency; and / or, The determining of the optimal volute profile by using a genetic algorithm comprises: determining the azimuth angle of the connection between the circular arc segment and the spiral segment and / or the average radius of the circular arc segment by using a genetic algorithm.

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