Method for locally modifying volute profile, volute, fan system and extractor hood

Abstract

The application discloses a local modification method of a volute profile, a volute, a fan system and a range hood. The local modification method of the volute profile comprises the following steps: taking the distance between a first point of an outlet of the volute and a position of 270 degrees of the volute profile as the major axis of an ellipse, and the ellipse passes through the first point and a volute tongue starting point; the first point is a point of the outlet of the volute far from the position of 270 degrees of the volute profile; judging whether a second point on the ellipse is in a preset range; if yes, connecting the first point, the second point and the volute tongue starting point through a smooth curve; if not, adjusting the extension direction of the major axis of the ellipse until the second point is in the preset range; the second point is the intersection of the extension line of the major axis of the ellipse and the position of 270 degrees of the volute profile close to the ellipse; and the preset range is related to the extension direction of the line connecting the first point and the volute tongue starting point, the extension direction of the major axis of the ellipse and the extension direction of the line connecting the first point and the position of 270 degrees of the volute profile.

Description

Technical Field

[0001] This invention relates to a method for partial modification of the volute profile, the volute, the fan system, and the range hood. Background Technology

[0002] The volute is one of the core components of a blower system. Its function is to guide the gas leaving the impeller to the volute outlet and convert some of the gas's kinetic energy into pressure energy. Firstly, traditional volute designs based on the Archimedean spiral assume steady fluid flow within the volute and neglect internal friction, which differs significantly from the viscous flow and inlet distortion of actual volutes. Therefore, traditional theoretical design methods for volutes are often not the optimal solution for the specific operating conditions. Typically, it is necessary to make local modifications to the volute design based on the Archimedean spiral, according to the streamline results obtained from simulations of the design conditions. For example... Figure 1 As shown, the traditional volute tongue design is typically an arc from a to b, with a radius generally r = 0.03~0.06D (D is the impeller outer diameter). Section bc is usually designed as a straight line, but here, due to the large angle of attack between the airflow guiding the volute outlet and the tongue, coupled with the diffusion effect at the volute outlet, the tongue using the traditional design method easily forms a large adverse pressure gradient near the volute outlet, resulting in local backflow. This causes some gas to circulate within the volute, reducing the flow rate and efficiency of the fan system. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the shortcomings of the existing technology where the bc section is designed as a straight line, but because the angle of attack between the airflow at the volute outlet and the volute tongue is large, coupled with the diffusion effect at the volute outlet, the volute tongue using the traditional design method is prone to forming a large reverse pressure gradient above the volute outlet, resulting in local backflow. This causes some gas to circulate inside the volute, reducing the flow rate and efficiency of the fan system. The invention provides a method for local modification of the volute profile, a volute, a fan system, and a range hood.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] This invention discloses a method for local modification of the volute profile, the method comprising:

[0006] An ellipse is drawn with the distance between the first point of the volute exit and the position of 270 degrees of the volute profile as the major diameter of the ellipse, and the ellipse passes through the starting point of the volute tongue and the first point, wherein the first point is a point in the volute exit that is far away from the position of 270 degrees of the volute profile.

[0007] Determine whether the second point on the ellipse is within a preset range. If yes, connect the first point, the second point, and the starting point of the volute tongue with a smooth curve. If no, adjust the extension direction of the ellipse until the second point is within the preset range. The second point is the intersection of the extension line of the major axis of the ellipse and the position of the ellipse close to the volute profile at 270 degrees. The preset range is related to the extension direction of the line connecting the first point and the starting point of the volute tongue, the extension direction of the major axis of the ellipse, and the extension direction of the line connecting the first point and the position of the volute profile at 270 degrees.

[0008] In this design, the above-mentioned modifications to the volute tongue reduce the impact of the high-speed airflow at the outlet, thereby reducing pressure pulsation near the volute tongue and thus lowering noise levels. Furthermore, the outward contraction of the volute tongue profile results in a shorter tongue and a smooth transition at the connection point, increasing the area of ​​the volute tongue. This reduces pressure drop at the volute tongue during fan operation, further decreasing the probability of noise generation.

[0009] Preferably, the preset range is defined by a first endpoint and a second endpoint, wherein the first endpoint is the position of the second point when the minor axis of the ellipse coincides with the line connecting the preset range, the first point, and the starting point of the volute tongue; and the second endpoint is the position of the second point when the ellipse is tangent to the line connecting the first point and the volute profile at a 270-degree angle.

[0010] In this solution, by adopting the above-mentioned form, when the second point is within the preset range, the impact of the high-speed airflow at the outlet on the volute tongue can be reduced, thereby reducing the pressure pulsation near the volute tongue and thus achieving the effect of reducing noise.

[0011] Preferably, the method for locally modifying the volute profile includes:

[0012] The volute profile tapers inward at a 90-degree angle, with the inward taper dimension being... ,and It is related to the radius of the original Archimedean spiral at the 90-degree position marked on the diagram;

[0013] right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 90 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 20 degrees.

[0014] right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the position of 90 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 20 degrees.

[0015] right They are connected by smooth curves to form smooth, contoured lines;

[0016] And / or,

[0017] The volute profile tapers inward at a position of 270 degrees, with the inward taper dimension being... ,and It is related to the radius of the original Archimedean spiral at the 90-degree position marked on the diagram;

[0018] right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 270 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 40 degrees.

[0019] right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotation counterclockwise from the position of 270 degrees from the volute profile. The angle, and The temperature should not exceed 60 degrees and should not be less than 25 degrees.

[0020] right They are connected by smooth curves to form smooth, contoured lines.

[0021] In this scheme, the above-mentioned modification of the volute profile at the 90-degree position can appropriately reduce the cross-sectional area of ​​the flow channel, which is beneficial for operating conditions with lower airflow rates and results in minimal performance degradation at maximum airflow rates. The contraction modification of the volute profile at the 270-degree position can effectively reduce boundary layer separation, which is beneficial for 12m... 3 Operating conditions with high back pressure (approximately 300 Pa) and airflow greater than 25 m³ / min, and outlet back pressure of 0 Pa. 3 The maximum airflow rate has been improved, which can simultaneously reduce noise and increase the flow rate and efficiency of the fan system.

[0022] Preferably, the inward contraction occurs at a 90-degree angle to the volute profile, wherein the inward contraction dimension is... ,and The radius of the original Archimedean spiral at the 90-degree mark on the diagram is related to the following:

[0023] According to the formula Find ,in Not greater than 0.03 and not less than 0.01, The radius of the original Archimedean spiral at the 90-degree mark on the diagram;

[0024] And / or,

[0025] The volute profile is contracted inward at a position of 270 degrees, wherein the inward contraction dimension is... ,and The radius of the original Archimedean spiral at the 90-degree mark on the diagram is related to the following:

[0026] According to the formula Find ,in Not greater than 0.05 and not less than 0.015, The radius of the original Archimedes spiral at the 90-degree mark on the diagram.

[0027] In this solution, the above-mentioned form can improve the efficiency of the working air volume condition to a certain extent, while having little impact on the performance such as air volume and efficiency during maximum air volume operation.

[0028] Preferably, the above The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 90 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 20 degrees, specifically including:

[0029] According to the formula Find ,in, The angle of the contraction position;

[0030] And / or,

[0031] The pair The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 270 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 40 degrees, specifically including:

[0032] According to the formula Find ,in, The angle of the contraction position; Not greater than 1.2 and not less than 1.

[0033] Preferably, the above The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the position of 90 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 20 degrees, specifically including:

[0034] According to the formula Find ,in, The angle of the contraction position; Not greater than 1.1 and not less than 1;

[0035] And / or,

[0036] right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotation counterclockwise from the position of 270 degrees from the volute profile. The angle, and The temperature shall not exceed 60 degrees and shall not be less than 25 degrees, specifically including:

[0037] According to the formula Find ,in, The angle of the contraction position; Not greater than 1 and not less than 0.7.

[0038] Preferably, the method for locally modifying the volute profile includes:

[0039] From the first end point of the first outlet of the volute, the volute profile extends away from the volute tongue and toward the air outlet, and intersects with the air outlet at a third point.

[0040] Extending from the third point along the direction of the line connecting the end point of the volute outlet and the third point towards the second outlet of the air duct, and intersecting with the outlet of the air duct at the fourth point;

[0041] Wherein, the second end point of the second outlet of the air duct is located between the projections of the fourth point and the third point onto the diameter of the second outlet passing through the second end point.

[0042] In this solution, the above-mentioned form can reduce the outlet flow resistance and flow separation intensity, thereby improving the working efficiency of the fan system.

[0043] Preferably, from the third point toward the direction closer to the first endpoint, the absolute value of the slope of the volute's profile gradually increases;

[0044] And / or, the slope change of the volute profile near the volute tongue is less than the slope of the volute profile away from the volute tongue.

[0045] In this solution, the kinetic energy of the fluid can be converted into pressure energy, thereby ensuring that the fluid can reduce flow losses and improve the working efficiency of the fan system.

[0046] The present invention provides a volute, wherein the volute employs a partial modification method for the volute profile as described in any of the preceding claims.

[0047] In this solution, the aforementioned form and the partial modification method of the volute profile allow for reasonable modification of the volute tongue, reducing the impact of the high-speed airflow at the outlet on the volute tongue and thus reducing pressure pulsation near the volute tongue, thereby reducing noise. Furthermore, the volute tongue profile is designed to contract outwards, resulting in a shorter volute tongue and a smooth transition at the connection point, thereby increasing the area of ​​the volute tongue. This reduces pressure drop at the volute tongue during fan operation, further decreasing the probability of noise generation.

[0048] The present invention also discloses a fan system, the fan system comprising the volute as described above.

[0049] In this solution, the volute of the fan system, using the aforementioned partial modification method of the volute profile, allows for reasonable modification of the volute tongue, reducing the impact of the high-speed airflow at the outlet on the volute tongue and thus reducing pressure pulsation near the volute tongue, thereby reducing noise. Furthermore, the volute tongue profile is designed to contract outwards, resulting in a shorter volute tongue and a smooth transition at the connection point, thereby increasing the area of ​​the volute tongue. This reduces pressure drop at the volute tongue during fan operation, further decreasing the probability of noise generation.

[0050] Preferably, the fan system further includes a motor made of neodymium iron boron.

[0051] In this solution, the above-mentioned form is adopted to reduce the flow resistance of the motor while ensuring the same motor efficiency, thereby improving the efficiency of the entire fan system.

[0052] The present invention further discloses a range hood, which includes the fan system described above.

[0053] In this design, the aforementioned shape allows for proper modification of the volute tongue, reducing the impact of high-speed airflow at the outlet and thus decreasing pressure pulsation near the tongue, thereby reducing noise. Furthermore, the outward contraction of the volute tongue profile results in a shorter tongue and a smooth transition at the connection point, increasing the tongue's surface area. This reduces pressure drop at the tongue during fan operation, further lowering the probability of noise generation.

[0054] The positive and progressive effects of this invention are as follows:

[0055] By properly modifying the volute tongue, the impact of the high-speed airflow at the outlet on the volute tongue can be reduced, thereby decreasing pressure pulsation near the volute tongue and thus reducing noise. Furthermore, by making the volute tongue profile taper outwards, resulting in a shorter volute tongue, and by providing a smooth transition at the connection point, the surface area of ​​the volute tongue is increased. This reduces pressure drop at the volute tongue during fan operation, further decreasing the probability of noise generation. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of a local modification method for the volute profile in the prior art.

[0057] Figure 2 This is a first schematic diagram of a method for partial modification of the volute profile according to an embodiment of the present invention.

[0058] Figure 3 This is a second schematic diagram of a method for partially modifying the volute profile according to an embodiment of the present invention.

[0059] Figure 4 This is a third schematic diagram of the partial modification method of the volute profile according to an embodiment of the present invention.

[0060] Figure 5 This is a fourth schematic diagram of the partial modification method of the volute profile according to an embodiment of the present invention.

[0061] Figure 6 This is the fifth schematic diagram of the partial modification method of the volute profile according to an embodiment of the present invention.

[0062] Figure 7 This is a flowchart of a method for partial modification of the volute profile according to an embodiment of the present invention.

[0063] Explanation of reference numerals in the attached figures:

[0064] Cochlear tongue origin a

[0065] First point c

[0066] Second point b

[0067] The position d of the volute profile at 90 degrees

[0068] Position e of 270 degrees of the volute profile

[0069] The position f of the volute profile at 0 degrees

[0070] Exit 1

[0071] First endpoint g

[0072] Air duct 2

[0073] Third point h

[0074] The projection of the third point

[0075] Air duct outlet 3

[0076] Fourth point i

[0077] Second endpoint j

[0078] Fourth point k Detailed Implementation

[0079] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments.

[0080] like Figure 2 , Figure 3 and Figure 7 As shown, this embodiment provides a method for local modification of the volute profile, which includes:

[0081] Step S1: Draw an ellipse with the distance between the first point of the volute exit and the volute profile at 270 degrees as the major diameter of the ellipse, and the ellipse passes through the starting point of the volute tongue and the first point, where the first point is a point in the volute exit that is far away from the volute profile at 270 degrees.

[0082] It should be noted that the outlet of the volute can be round, square, or other shapes, and the first point is one of the points located 270 degrees away from the volute profile among the multiple volute outlets.

[0083] Step S2: Determine whether the second point on the ellipse is within the preset range. If yes, connect the first point, the second point, and the starting point of the volute tongue with a smooth curve. If no, adjust the extension direction of the major axis of the ellipse until the second point is within the preset range. The second point is the intersection of the extension line of the major axis of the ellipse and the position of the ellipse close to the volute profile at 270 degrees. The preset range is related to the extension direction of the line connecting the first point and the starting point of the volute tongue, the extension direction of the major axis of the ellipse, and the extension direction of the line connecting the first point and the position of the volute profile at 270 degrees.

[0084] In practical use, the preset range is defined by the first endpoint and the second endpoint. The first endpoint is the position of the second point when the minor axis of the ellipse coincides with the line connecting the first point and the starting point of the volute tongue. The second endpoint is the position of the second point when the ellipse is tangent to the line connecting the first point and the volute profile at 270 degrees.

[0085] It should be specifically noted that the aforementioned adjustment of the major axis extension direction of the ellipse refers to the change in the extension direction of the major axis when the ellipse is rotated. Furthermore, the starting point of the volute tongue is determined during the design of the volute casing.

[0086] By employing the above-described design, the impact of the high-speed airflow at the outlet on the volute tongue can be reduced, thereby decreasing pressure pulsation near the volute tongue and thus reducing noise. Furthermore, the volute tongue profile is designed to taper outwards, resulting in a shorter volute tongue. A smooth transition at the connection point increases the surface area of ​​the volute tongue, reducing pressure drop during fan operation and further decreasing the probability of noise generation.

[0087] The local modification methods for the volute profile include the modification method at the 90-degree position of the volute profile and the modification method at the 270-degree position of the volute profile.

[0088] like Figure 4 As shown, the modification method at the 90-degree position of the volute profile includes:

[0089] Step S10: The volute profile is contracted inward at a 90-degree angle, wherein the inward contraction dimension is... ,and The radius of the Archimedean spiral at the 90-degree mark on the original reference diagram is related to the radius of the spiral. In practical application, it is determined according to the formula. Find ,in Not greater than 0.03 and not less than 0.01, The radius of the original Archimedes spiral at the 90-degree mark on the diagram.

[0090] Step S20, for The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the 90-degree position of the volute profile. The angle, and The angle should not exceed 90 degrees and should not be less than 20 degrees; in specific applications, refer to the formula. Find ,in, The angle of the contraction position;

[0091] Step S30, for The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the 90-degree position of the volute profile. The angle, and The angle should not exceed 90 degrees and should not be less than 20 degrees; in specific applications, refer to the formula. Find ,in, The angle of the contraction position; Not greater than 1.1 and not less than 1.

[0092] Step S40, for They are connected by smooth curves to form smooth, contoured lines;

[0093] In practical applications, modifying the volute profile at the 90-degree angle as described above can appropriately reduce the cross-sectional area of ​​the flow channel, which is beneficial for operating conditions with lower airflow rates and results in less performance degradation under maximum airflow conditions. Specifically, in When positioned, shrinkage size At its maximum, the shrinkage dimension is at its front and rear positions in the circumferential direction. With the circumferential angle at a distance of 90° It gradually decreases as the value increases. For determining the radius of the local contraction profile at different locations, in... and Within the range, take two to four control points at equal angles (for example, the number of upstream and downstream control points is 2 on average). , The angular spacing between each control point is then... The curve has a total of 5 control points. For Within the 90° upstream modification range, the inner diameter of the control point Follow It decreases linearly as it increases.

[0094] It should be noted that steps S10, S20, and S30 represent three separate steps, not a specific order. In other words, these three steps can be performed simultaneously, or one step can precede the other two. Furthermore, the smooth curve mentioned above refers to a continuous curve without sharp points or breaks in the general sense.

[0095] like Figure 4 As shown, the modification method at the 270-degree position of the volute profile includes:

[0096] Step S50: The volute profile is contracted inward at a position of 270 degrees, wherein the inward contraction dimension is... ,and The radius of the Archimedean spiral at the 90-degree mark on the original reference diagram is related to the radius of the spiral. In practical application, it is determined according to the formula. Find ,in Not greater than 0.05 and not less than 0.015, The radius of the original Archimedes spiral at the 90-degree mark on the diagram.

[0097] Step S60, for The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from 270 degrees of the volute profile. The angle, and The angle should not exceed 90 degrees and should not be less than 40 degrees; in specific applications, refer to the formula. Find ,in, The angle of the contraction position; Not greater than 1.2 and not less than 1.

[0098] Step S70, for The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the 270-degree position of the volute profile. The angle, and The temperature should not exceed 60 degrees and should not be less than 25 degrees; in specific applications, refer to the formula. Find ,in, The angle of the contraction position; Not greater than 1 and not less than 0.7.

[0099] Step 80, to They are connected by smooth curves to form smooth, contoured lines.

[0100] In practical applications, employing the above structural form and modifying the volute profile at the 270-degree position can effectively reduce boundary layer separation, especially for 12m... 3 Operating conditions with high back pressure (approximately 300 Pa) and airflow greater than 25 m³ / min, and outlet back pressure of 0 Pa. 3 The maximum airflow rate has been improved, reducing noise while simultaneously increasing the flow rate and efficiency of the fan system. Specifically, At that time, it exhibits good overall performance. Regarding the starting angle of the second modification, there is... (where the starting angle and ending angle of contraction are respectively) and Similarly, two to four control points with equal angles are taken upstream and downstream of the contraction profile. After determining the coordinates of each starting point and intermediate control point using the above formula, a smooth profile can be formed by connecting them with smooth cubic splines.

[0101] It should be noted that steps S50, S60, and S70 represent three separate steps, not necessarily in any particular order. In other words, these three steps can be performed simultaneously, or one step can precede the other two. Furthermore, the smooth curve mentioned above refers to a continuous curve without sharp points or breaks in the general sense.

[0102] In practice, , Three control points are set on the upstream arc at 90°, and two control points are set on the downstream arc. , Four control points are set 180° upstream and three control points are set downstream. The position of each control point is determined by the angle based on the starting and ending positions of the shrinkage modification and the number of control points. The specific shrinkage size is determined by comprehensively considering the calculation method mentioned above and the smoothness requirements of the simulated streamlines and local profiles.

[0103] This embodiment compares the simulation results with those of existing technologies that modify the original Archimedes spiral design. A comparison of airflow, static pressure, and efficiency at the two main design points—maximum airflow and operating airflow—shows that the modified volute, under maximum airflow conditions, experiences a slight increase in airflow at the same rotational speed, while the efficiency decreases by 1% compared to the original volute. However, the airflow is slightly higher at the same rotational speed. Under operating airflow conditions, the static pressure increases by 10 Pa, and the efficiency improves by 1.13%. Furthermore, testing confirms the simulation results, showing an approximately 1.0% efficiency improvement and a 0.5 dB noise reduction under operating airflow conditions. Maximum airflow condition (0 Pa back pressure, 32.9 m³ / h) 3 The efficiency and noise level are basically the same as the original machine (around 18.7 m³ / min), with an outlet pressure of 0 Pa and a flow rate of 18.7 m³ / min. 3 Under relatively low flow conditions of around / min, the efficiency is increased by about 0.5% and the noise is reduced by about 0.3dB at the same air volume.

[0104] Table 1. Comparison of simulation performance between the original Archimedes spiral scheme and the optimized modified scheme.

[0105]

[0106] like Figure 5 and Figure 6 As shown, the local modification methods for the volute profile include:

[0107] Step S100: Extend from the first end of the first outlet 1 of the volute along the volute profile away from the volute tongue towards the air outlet 2, and intersect with the air outlet 2 at the third point.

[0108] Step S200: Extend from the third point along the direction of the line connecting the end point of the volute outlet and the third point towards the second outlet of the air outlet 2, and intersect with the outlet 3 of the air outlet 3 at the fourth point.

[0109] The second end point of the second outlet of the air outlet 2 is located between the projections of the fourth point and the third point onto the diameter of the second outlet passing through the second end point.

[0110] In practical applications, adopting the above-mentioned method can reduce outlet flow resistance and flow separation intensity, thereby improving the working efficiency of the fan system.

[0111] In practical implementation, from the third point towards the first endpoint, the absolute value of the slope of the volute profile gradually increases; the slope change of the volute profile near the volute tongue in the air outlet duct 2 is less than the slope of the volute profile away from the volute tongue in the air outlet duct 2. By adopting the above method, the kinetic energy of the fluid can be converted into pressure energy, thereby ensuring that the fluid can reduce flow losses and improving the working efficiency of the fan system.

[0112] This embodiment also provides a volute, wherein the volute employs any of the above-described volute profile modification methods. By employing the above-described form, the volute, using the aforementioned volute profile modification method, can reasonably modify the volute tongue, reducing the impact of the high-speed airflow at the outlet on the volute tongue, thereby reducing pressure pulsation near the volute tongue and thus reducing noise. Furthermore, by achieving an outward contraction effect in the volute tongue profile, the volute tongue is designed to be shorter, and a smooth transition is provided at the connection point, thereby increasing the area of ​​the volute tongue. This reduces the pressure drop at the volute tongue during fan operation, thereby reducing the probability of noise generation.

[0113] This embodiment also provides a fan system, which includes the volute as described above. By employing the aforementioned method of partially modifying the volute profile, the impact of the high-speed airflow at the outlet on the volute tongue can be reduced, thereby decreasing pressure pulsation near the volute tongue and reducing noise. Furthermore, the volute tongue profile is designed to contract outwards, resulting in a shorter volute tongue and a smooth transition at the connection point, thus increasing the area of ​​the volute tongue. This reduces pressure drop at the volute tongue during fan operation, further decreasing the probability of noise generation.

[0114] The fan system also includes a motor made of neodymium iron boron. By adopting this design, while maintaining the same motor efficiency, the flow resistance of the motor is reduced, thus improving the overall efficiency of the fan system.

[0115] This embodiment further provides a range hood, which includes the aforementioned fan system. By employing the above-described design, the impact of the high-speed airflow at the outlet on the volute can be reduced, thereby decreasing pressure pulsation near the volute and thus reducing noise. Furthermore, the volute profile is designed to taper outwards, resulting in a shorter volute and a smooth transition at the connection point, thereby increasing the area of ​​the volute. This reduces pressure drop at the volute during fan operation, further decreasing the probability of noise generation.

[0116] For range hoods, two motors are used: a ferrite-based 108 motor and a neodymium iron boron (NdFeB)-based 97mm motor. Their model dimensions and related parameters are shown in the table below. A comparison of dimensions and weight shows that the NdFeB-97mm motor is relatively smaller, yet boasts higher maximum torque and power, while maintaining a lighter weight. This allows for a larger airflow and reduces blockage in the fan system. Furthermore, the reduced weight also lowers vibration and noise levels.

[0117] Table 2 Design performance parameters for ferrite-Φ108mm motors and neodymium iron boron-Φ97mm motors

[0118]

[0119] Based on the electromagnetic design, the efficiency of ferrite-Φ108mm and neodymium iron boron-Φ97mm motors under different operating conditions was simulated. The efficiency distribution map of these motors is shown in the figure below. The efficiency gradually increases from blue to green and then to red. Simulation results show that the neodymium iron boron-Φ97mm motor has a larger high-efficiency region and a smaller low-efficiency region, enabling it to operate efficiently across a wider range of operating conditions.

[0120] Table 3 shows the performance of the two motors at a maximum airflow (29m³ / h) in the range hood. 3 / min) and working air volume conditions (12m 3 Performance comparison at the same speed ( / min). Under high airflow operating speed conditions, the NdFeB-Φ97mm motor exhibits higher output torque and power with lower current and input power. Due to the lower current, overall energy loss is reduced, resulting in a 9.47% increase in absolute motor efficiency. At the same speed for high airflow conditions, the NdFeB-Φ97mm motor is 1.28% less efficient than the ferrite motor. However, due to the smaller motor size and reduced airflow obstruction, the total pressure efficiency of the range hood system actually increases by 0.61%, indicating a significant positive aerodynamic benefit.

[0121] Table 3 Test results of the motor near high air volume and working air volume conditions.

[0122]

[0123] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for local modification of the volute profile, characterized in that, The method for locally modifying the volute profile includes: An ellipse is drawn with the distance between the first point of the volute exit and the position of 270 degrees of the volute profile as the major diameter of the ellipse, and the ellipse passes through the starting point of the volute tongue and the first point, wherein the first point is a point in the volute exit that is far away from the position of 270 degrees of the volute profile. Determine whether the second point on the ellipse is within a preset range. If yes, connect the first point, the second point, and the starting point of the volute tongue with a smooth curve. If no, adjust the extension direction of the major axis of the ellipse until the second point is within the preset range. The second point is the intersection of the extension line of the major axis of the ellipse and the position of the ellipse close to the volute profile at 270 degrees. The preset range is related to the extension direction of the line connecting the first point and the starting point of the volute tongue, the extension direction of the major axis of the ellipse, and the extension direction of the line connecting the first point and the position of the volute profile at 270 degrees.

2. The method for partial modification of the volute profile as described in claim 1, characterized in that, The preset range is defined by a first endpoint and a second endpoint, wherein the first endpoint is the position of the second point when the minor axis of the ellipse coincides with the line connecting the first point and the starting point of the volute tongue; the second endpoint is the position of the second point when the ellipse is tangent to the line connecting the first point and the volute profile at a 270-degree angle.

3. The method for partial modification of the volute profile as described in claim 1, characterized in that, The method for locally modifying the volute profile includes: The volute profile tapers inward at a 90-degree angle, with the inward taper dimension being... ,and It is related to the radius of the original Archimedean spiral at the 90-degree position marked on the diagram; right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 90 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 20 degrees. right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the position of 90 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 20 degrees. right They are connected by smooth curves to form smooth, contoured lines; And / or, The volute profile tapers inward at a position of 270 degrees, with the inward taper dimension being... ,and It is related to the radius of the original Archimedean spiral at the 90-degree position marked on the diagram; right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 270 degrees from the volute profile. The angle, and The temperature shall not exceed 90 degrees and shall not be less than 40 degrees. right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotation counterclockwise from the position of 270 degrees from the volute profile. The angle, and The temperature should not exceed 60 degrees and should not be less than 25 degrees. right They are connected by smooth curves to form smooth, contoured lines.

4. The method for partial modification of the volute profile as described in claim 3, characterized in that, The volute profile is contracted inward at a 90-degree angle, wherein the inward contraction dimension is... ,and The radius of the original Archimedean spiral at the 90-degree mark on the diagram is related to the following: According to the formula Find ,in Not greater than 0.03 and not less than 0.01, The radius of the original Archimedean spiral at the 90-degree mark on the diagram; And / or, The volute profile is contracted inward at a position of 270 degrees, wherein the inward contraction dimension is... ,and The radius of the original Archimedean spiral at the 90-degree mark on the diagram is related to the following: According to the formula Find ,in Not greater than 0.05 and not less than 0.015, The radius of the original Archimedes spiral at the 90-degree mark on the diagram.

5. The method for partial modification of the volute profile as described in claim 3, characterized in that, The pair The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 90 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 20 degrees, specifically including: According to the formula Find ,in, The angle of the contraction position; And / or, the pair The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating clockwise from the position of 270 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 40 degrees, specifically including: According to the formula Find ,in, The angle of the contraction position; Not greater than 1.2 and not less than 1.

6. The method for partial modification of the volute profile as described in claim 3, characterized in that, The pair The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotating counterclockwise from the position of 90 degrees from the volute profile. The angle, and The angle is not greater than 90 degrees and not less than 20 degrees, specifically including: According to the formula Find ,in, The angle of the contraction position; Not greater than 1.1 and not less than 1; And / or, right The volute profile within the range contracts inward, with the inward contraction dimension being... ,and and The angle of the contraction position and Relevant; among them Rotation counterclockwise from the position of 270 degrees from the volute profile. The angle, and The temperature shall not exceed 60 degrees and shall not be less than 25 degrees, specifically including: According to the formula Find ,in, The angle of the contraction position; Not greater than 1 and not less than 0.

7.

7. The method for partial modification of the volute profile as described in claim 1, characterized in that, The method for locally modifying the volute profile includes: From the first end point of the first outlet of the volute, the volute profile extends away from the volute tongue and toward the air outlet, and intersects with the air outlet at a third point. Extending from the third point along the direction of the line connecting the end point of the volute outlet and the third point towards the second outlet of the air duct, and intersecting with the outlet of the air duct at the fourth point; Wherein, the second end point of the second outlet of the air duct is located between the projections of the fourth point and the third point onto the diameter of the second outlet passing through the second end point.

8. The method for partial modification of the volute profile as described in claim 7, characterized in that, From the third point toward the first endpoint, the absolute value of the slope of the volute's profile gradually increases; And / or, the slope change of the volute profile near the volute tongue is less than the slope of the volute profile away from the volute tongue.

9. A volute, characterized in that, The volute is constructed using the partial modification method for the volute profile as described in any one of claims 1-8.

10. A fan system, characterized in that, The fan system includes the volute as described in claim 9.

11. The fan system as described in claim 10, characterized in that, The fan system also includes a motor, which is made of neodymium iron boron.

12. A range hood, characterized in that, The range hood includes the fan system as described in claim 10 or 11.

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