Volute profile generation method, fan volute, centrifugal fan and extractor hood

Abstract

The application provides a volute profile generation method, a fan volute, a centrifugal fan and an extractor hood. The method comprises the following steps: obtaining the maximum opening degree of the fan volute; sequentially drawing a first circular arc line, a second circular arc line, a third circular arc line and a fourth circular arc line based on the maximum opening degree of the fan volute; the first circular arc line, the second circular arc line, the third circular arc line and the fourth circular arc line are sequentially and smoothly connected; the first circular arc line has a first arc maximum opening degree, and the first arc maximum opening degree is equal to the maximum opening degree of the fan volute; the second circular arc line has a second arc maximum opening degree; the third circular arc line has a third arc maximum opening degree; the fourth circular arc line has a fourth arc maximum opening degree; and the first arc maximum opening degree, the second arc maximum opening degree, the third arc maximum opening degree and the fourth arc maximum opening degree sequentially decrease. The volute profile is drawn in the counterclockwise direction, the width of the fan rack can be fully utilized, and the volume of the fan volute is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of range hood, and particularly relates to a volute profile generation method, a fan volute, a centrifugal fan and a range hood. BACKGROUND

[0002] The range hood can suck oil fume, water vapor and the like generated in a cooking process and discharge them to the outdoor through a centrifugal fan. The centrifugal fan is an important core component of the range hood, and its function is to concentrate, guide and convert the dynamic pressure of the airflow into static pressure. The design of the centrifugal fan directly affects the performance of the range hood.

[0003] Please refer to Figure 1 , the related technology provides a centrifugal fan volute. The volute profile of the centrifugal fan volute includes a starting line AC at one end of the profile and an ending line MN at the other end of the profile. The starting line AC and the ending line MN are adjacent to the fan air outlet, and the starting line AC is located near the volute tongue. The volute profile further includes a first spiral line CD and a second spiral line EM. The first spiral line CD is connected with the starting line AC, and the second spiral line EM is connected with the ending line MN. The volute profile is designed in a forward direction, that is, the starting line AC is drawn first, and then the first spiral line CD, the straight line DE and the second spiral line EM are drawn in sequence in a clockwise direction.

[0004] When the fan volute is installed, a certain gap is usually required between the fan volute and the left and right sides of the fan frame. When the volute profile is designed in the forward direction, the maximum opening of the first spiral line CD is smaller than the maximum opening of the second spiral line EM. When the gap between the first spiral line CD and the fan frame is too small, the second spiral line EM is likely to interfere with the fan frame, and even the second spiral line EM exceeds the range of the fan frame. When the gap between the first spiral line CD and the fan frame is too large, the width of the fan frame cannot be effectively utilized, resulting in a smaller volute volume. SUMMARY

[0005] The present application aims to provide a volute profile generation method, a fan volute, a centrifugal fan and a range hood to solve the above problems. The present application achieves the above-mentioned purpose through the following technical solutions.

[0006] In a first aspect, the embodiments of the present application provide a method for generating a volute profile of a fan volute, the method comprising: obtaining a maximum opening degree of the fan volute; sequentially drawing a first circular arc line, a second circular arc line, a third circular arc line and a fourth circular arc line based on the maximum opening degree of the fan volute; wherein the first circular arc line, the second circular arc line, the third circular arc line and the fourth circular arc line are sequentially smoothly connected; the first circular arc line has a first arc maximum opening degree, and the first arc maximum opening degree is equal to the maximum opening degree of the fan volute; the second circular arc line has a second arc maximum opening degree; the third circular arc line has a third arc maximum opening degree; the fourth circular arc line has a fourth arc maximum opening degree; and the first arc maximum opening degree, the second arc maximum opening degree, the third arc maximum opening degree and the fourth arc maximum opening degree sequentially decrease.

[0007] In a second aspect, the embodiments of the present application provide a fan volute, comprising a first cover plate, a second cover plate and a surrounding plate, the first cover plate and the second cover plate are oppositely arranged, and the surrounding plate is connected between the first cover plate and the second cover plate; a profile line of an inner side surface of the surrounding plate is a volute profile, and the volute profile is generated according to the method of the first aspect.

[0008] In a third aspect, the embodiments of the present application provide a centrifugal fan, comprising a fan impeller and the fan volute of the second aspect, and the fan impeller is installed in the fan volute.

[0009] In a fourth aspect, the embodiments of the present application provide a range hood, comprising a fan frame and the centrifugal fan of the third aspect, and the centrifugal fan is installed in the fan frame.

[0010] The volute profile generation method, the fan volute, the centrifugal fan and the range hood provided by the embodiments of the present application first obtain the maximum opening degree of the fan volute, then sequentially draw the first circular arc line, the second circular arc line, the third circular arc line and the fourth circular arc line based on the maximum opening degree of the fan volute, wherein the maximum opening degrees corresponding to the first circular arc line, the second circular arc line, the third circular arc line and the fourth circular arc line sequentially decrease, which is equivalent to that the starting profile of the volute is on the opposite side of the volute tongue, and then the volute profile is drawn in the counterclockwise direction, so that the width of the fan frame can be fully utilized and the volume of the fan volute can be increased. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0012] Figure 1 A volute profile diagram of a centrifugal fan volute provided by the related art.

[0013] Figure 2 This is a schematic diagram of the structure of the range hood provided in the embodiment of this application.

[0014] Figure 3 for Figure 2 The diagram shows the internal structure of the range hood.

[0015] Figure 4 This is a schematic diagram of the structure of the fan volute provided in an embodiment of this application.

[0016] Figure 5 This is a schematic diagram of the volute profile of a wind turbine volute provided in an embodiment of this application.

[0017] Figure 6 This is a flowchart illustrating the method for generating volute profiles provided in an embodiment of this application.

[0018] Figure 7 This is another schematic flowchart of the method for generating volute profiles provided in an embodiment of this application.

[0019] Figure 8 This is another schematic flowchart of the method for generating volute profiles provided in the embodiments of this application.

[0020] Figure 9 This is a schematic diagram of the volute profile of a wind turbine volute provided for another embodiment of this application.

[0021] Figure 10 A comparison diagram of the volute profile drawn for the forward and reverse designs provided in the embodiments of this application. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0024] In order to better understand the volute profile generation method, the fan volute and the centrifugal fan provided by the embodiments of the present application, the range hood provided by the embodiments of the present application is described first below, and the volute profile generation method, the fan volute and the centrifugal fan are applicable to the range hood.

[0025] Please refer to Figure 2 and Figure 3 , the present application provides a range hood 100, the range hood 100 includes a fan frame 110 and a centrifugal fan 200, the centrifugal fan 200 is installed in the fan frame 110.

[0026] The bottom of the fan frame 110 is provided with an air inlet 111. The range hood 100 further includes a check valve 120, the check valve 120 is installed on the top of the fan frame 110, and the centrifugal fan 200 is installed between the air inlet 111 and the check valve 120. When the range hood 100 starts to work, the oil fume, water vapor and the like generated during cooking can be sucked from the air inlet 111 by the action of the centrifugal fan 200, and then the sucked oil fume, water vapor and the like are discharged from the check valve 120 into the public flue. When the range hood 100 stops working, the check valve 120 automatically closes, isolating the oil fume channel from the public flue, so that the oil in the public flue cannot flow back into the range hood 100.

[0027] Please refer to Figure 3 and Figure 4 , the centrifugal fan 200 includes a fan impeller 210, a fan volute 300 and a driving motor 220, the fan impeller 210 is rotatably installed in the fan volute 300, and the driving motor 220 is in driving cooperation with the fan impeller 210 for driving the fan impeller 210 to rotate.

[0028] The fan volute 300 can include a first cover plate 310, a second cover plate 320 and a surrounding plate 330, the first cover plate 310 and the second cover plate 320 are oppositely arranged, and the surrounding plate 330 is connected between the first cover plate 310 and the second cover plate 320. The profile line of the inner side profile of the surrounding plate 330 is a volute profile 340 (see Figure 5 ). The outer shapes of the first cover plate 310 and the second cover plate 320 are substantially the same, and the second cover plate 320 can be provided with a motor fixing hole 321, and the driving motor 220 is fixed in the motor fixing hole 321.

[0029] The fan frame 110 can include a first panel 111 (see Figure 2The first panel 111, the second panel 112, the third panel 113 and the fourth panel (not labeled in the view) are oppositely arranged, the second panel 112 is connected to one side of the first panel 111 and the fourth panel, and the second panel 112 can be perpendicular to the first panel 111 and the fourth panel; the third panel 113 is connected to the other side of the first panel 111 and the fourth panel, and the third panel 113 can be perpendicular to the first panel 111 and the fourth panel, so as to form a cuboid structure. The second panel 112 and the third panel 113 can be opposite along the width direction of the fan rack 110, and the width of the fan rack 110 is equal to the distance between the second panel 112 and the third panel 113.

[0030] When the centrifugal fan 200 is installed in the fan rack 110, the first cover plate 310 can face the first panel 111, the second cover plate 320 faces the fourth panel, one side of the surrounding plate 330 faces the second panel 112, and a certain gap is reserved between the surrounding plate 330 and the second panel 112, and the other side of the surrounding plate 330 faces the third panel 113, and a certain gap is reserved between the surrounding plate 330 and the third panel 113.

[0031] Please refer to Figure 5 and Figure 6 The embodiment of the application further provides a method for generating a volute profile of a fan volute 300, which can include the following steps S110 and S120.

[0032] Step S110, obtaining the maximum opening degree H0 of the fan volute 300.

[0033] Step S120, sequentially drawing a first circular arc line AB, a second circular arc line BC, a third circular arc line CD and a fourth circular arc line DE based on the maximum opening degree H0 of the fan volute 300; wherein the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE are sequentially and smoothly connected, the first circular arc line AB has a first arc line maximum opening degree H1, and the first arc line maximum opening degree H1 is equal to the maximum opening degree H0 of the fan volute, the second circular arc line BC has a second arc line maximum opening degree H2, the third circular arc line CD has a third arc line maximum opening degree H3, the fourth circular arc line DE has a fourth arc line maximum opening degree H4, and the first arc line maximum opening degree H1, the second arc line maximum opening degree H2, the third arc line maximum opening degree H3 and the fourth arc line maximum opening degree H4 decrease in turn, that is, H1>H2>H3>H4.

[0034] The first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE are smoothly connected in sequence, which means that the first circular arc line AB and the second circular arc line BC are tangent at the intersection point B, the second circular arc line BC and the third circular arc line CD are tangent at the intersection point C, and the third circular arc line CD and the fourth circular arc line DE are tangent at the intersection point D.

[0035] The maximum opening degree H0 of the fan volute 300 is also referred to as the opening degree of the terminal section of the fan volute. A plane coordinate system is established with the center O of the fan impeller 210 as the origin, the X-axis direction is consistent with the width direction of the fan frame 110, and the positive direction of the X-axis points to the third panel 113; the Y-axis direction is consistent with the height direction of the fan frame 110, and the positive direction of the Y-axis points to the top of the fan frame 110.

[0036] The air outlet of the fan volute 300 is located in the second quadrant. The first circular arc line AB is located in the second quadrant and the third quadrant, and the first circular arc line AB intersects the negative half of the X-axis at the A1 point. The maximum opening degree H1 of the first arc line is equal to the distance value of the first circular arc line AB and the fan impeller 210 on the negative half of the X-axis. The second circular arc line BC is located in the fourth quadrant, and the second circular arc line BC intersects the negative half of the Y-axis at the B point. The maximum opening degree H2 of the second arc line is equal to the distance value of the second circular arc line BC and the fan impeller 210 on the negative half of the Y-axis. The third circular arc line CD is located in the first quadrant, and the third circular arc line CD intersects the positive half of the X-axis at the C point. The maximum opening degree H3 of the third arc line is equal to the distance value of the third circular arc line CD and the fan impeller 210 on the positive half of the X-axis. The fourth circular arc line DE is located in the second quadrant, and the fourth circular arc line DE intersects the positive half of the Y-axis at the D point. The maximum opening degree H4 of the fourth arc line is equal to the distance value of the fourth circular arc line DE and the fan impeller 210 on the positive half of the Y-axis.

[0037] When the fan volute 300 is installed in the fan frame 110, the first circular arc line AB is adjacent to the second panel 112, and there is a certain gap between the first circular arc line AB and the second panel 112. The third circular arc line CD is adjacent to the third panel 113, and there is a certain gap between the third circular arc line CD and the third panel 113.

[0038] The volute profile generation method provided in the embodiments of the present application first acquires the maximum opening degree H0 of the fan volute 300, then sequentially draws a first circular arc line AB, a second circular arc line BC, a third circular arc line CD and a fourth circular arc line DE based on the maximum opening degree H0 of the fan volute 300, wherein the maximum opening degrees corresponding to the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE sequentially decrease, which is equivalent to that the starting profile of the fan volute 300 is on the opposite side of the volute tongue, then the volute profile 340 is drawn in the counterclockwise direction, and since the maximum opening degree H3 of the third arc line is less than the maximum opening degree H1 of the first arc line, a certain gap is left between the first circular arc line AB and the second panel 112, which can ensure that there is enough gap between the third circular arc line CD and the fourth panel, thereby avoiding the situation that the volute profile 340 is not complete and has a cut edge (i.e., the volute profile 340 does not include a straight line segment), and the width of the fan rack 110 can be fully utilized to increase the volume of the volute while ensuring that a certain gap is reserved between the fan volute 300 and the fan rack 110.

[0039] In the embodiments, the volute profile 340 can only include the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE, that is, the volute profile 340 is composed of the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE, so that the volute profile 340 is entirely composed of circular arc lines, avoiding the situation of cutting edge, so that there is no local flow field pressure and velocity mutation, and the smoothness of the airflow collection and passing in the volute is improved.

[0040] In the embodiments, the volute profile 340 further includes a first straight line LA at one end of the volute profile 340 and a second straight line EF at the other end of the volute profile 340, the first straight line LA is connected to the starting point A of the first circular arc line AB, and the first straight line LA is tangent to the first circular arc line AB at the starting point A, and the second straight line segment EF is smoothly connected to the fourth circular arc line DE and presents an arc transition. The first straight line LA and the second straight line EF are beneficial to the conversion of dynamic pressure to static pressure in the fan volute 300, and can reduce energy loss.

[0041] In some embodiments, the included angle β of the line connecting the starting point A of the first circular arc line AB and the center O of the fan impeller 210 with respect to the horizontal reference line (X-axis) satisfies the relationship: 0°≤β≤24°. For example, the included angle β can be equal to 0°, 10°, 15°, 20° or 24°, etc.

[0042] The included angle β determines the expansion angle of the volute outlet, the smaller the included angle β, the larger the expansion angle, and the larger the included angle β, the smaller the expansion angle. After multiple designs and attempts, it is found that controlling the included angle β in the range of 0°-24° can not only meet the requirements of the centrifugal fan 200 on air volume and air pressure, but also maximize the reduction of energy consumption and control noise.

[0043] Please refer to Figure 3 , Figure 5 and Figure 7 , in some embodiments, the above step S110 can specifically include the following steps S111 and S112.

[0044] Step S111, determine the relative position relationship between the fan impeller 210 and the fan frame 110.

[0045] The volute profile 340 of the fan volute 300 is designed based on the outer diameter and the center of the fan impeller 210. When designing the volute profile 340, the outer diameter and the center of the fan impeller 210 need to be confirmed first, and then the relative position relationship between the fan impeller 210 and the fan frame 110 is determined, that is, the installation position of the fan impeller 210 on the fan frame 110 is determined, so that the position of the center of the fan impeller 210 on the fan frame 110 can be determined, and the distance m between the center of the fan impeller 210 and the second panel 112 can be obtained.

[0046] Step S112, determine the maximum opening degree H0 of the fan volute 300 according to the diameter Φ of the fan impeller 210 and the width of the fan frame 110.

[0047] Specifically, after determining the relative position relationship between the fan impeller 210 and the fan frame 110, the reserved gap n between the first circular arc AB and the second panel 112 needs to be considered, and the maximum opening degree H0 of the fan volute 300 can be calculated according to the relationship m=n+H0+Φ / 2. Thus, the maximum opening degree H0 of the fan volute 300 can be accurately calculated according to the reserved gap of the fan volute 300 and the fan frame 110, and the width of the fan frame 110 is fully utilized, so that the volume of the fan volute 300 reaches the maximum.

[0048] Please refer to Figure 3 , Figure 5 and Figure 8 , in some embodiments, the above step S120 can specifically include the following steps S121 to S125.

[0049] Step S121, determine the first center O1 of the first circular arc AB, the second center O2 of the second circular arc BC, the third center O3 of the third circular arc CD and the fourth center O4 of the fourth circular arc DE based on the maximum opening degree H0 of the fan volute 300.

[0050] As an implementation, the first square, the second square, the third square and the fourth square can be drawn based on the center O of the fan impeller 210 and the maximum opening H0 of the fan volute 300; the first square is located in the first quadrant, and adjacent two sides of the first square are located on the positive half of the X-axis and the positive half of the Y-axis, respectively; the second square is located in the fourth quadrant, and adjacent two sides of the second square are located on the positive half of the X-axis and the negative half of the Y-axis, respectively; the third square is located in the third quadrant, and adjacent two sides of the third square are located on the negative half of the X-axis and the negative half of the Y-axis, respectively; the fourth square is located in the second quadrant, and adjacent two sides of the fourth square are located on the negative half of the X-axis and the positive half of the Y-axis, respectively; the side length of the first square is a, the side length of the second square is b, the side length of the third square is c, and the side length of the fourth square is d, and a < b < c < d, |a-b|=|b-c|=|c-d|.

[0051] The center O of the fan impeller 210 and the first center O1 are located at the opposite corners of the fourth square, the center O of the fan impeller 210 and the second center O2 are located at the opposite corners of the third square, the center O of the fan impeller 210 and the third center O3 are located at the opposite corners of the second square, and the center O of the fan impeller 210 and the fourth center O4 are located at the opposite corners of the first square.

[0052] The specific values of the side lengths a, b, c and d are determined according to the maximum opening H0 of the fan volute 300. For example, a = 0.0999H0, b = 0.1166H0, c = 0.1333H0, and d = 0.15H0, and |a-b|=|b-c|=|c-d|=0.0167H0. Of course, in other embodiments, the absolute values of the differences between a and b, between b and c, and between c and d can not be equal, but can be controlled within a certain difference range, for example, |(a-b)-(b-c)|≤0.1 and |(b-c)-(c-d)|≤0.1. The smaller the difference is, the closer the volute profile 340 composed of the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE is to the Archimedes spiral, and when |a-b|=|b-c|=|c-d|, the volute profile 340 composed of the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE is closest to the Archimedes spiral.

[0053] In this embodiment, |a-b| = |b-c| = |c-d|, that is, the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE have the same change curvature, and the difference between a and b, the difference between b and c and the difference between c and d change regularly, so that the volute profile 340 composed of the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE is closer to the Archimedes spiral, so as to reduce the air flow resistance and reduce the noise.

[0054] In this embodiment, the volute tongue gap t and the diameter Φ of the fan impeller 210 can satisfy the relationship: 0.03 ≤ t / Φ ≤ 0.05. For example, t / Φ is equal to 0.03, 0.035, 0.04, 0.045 or 0.05, etc. Thus, the smoothness inside the fan volute 300 can be improved, and the maximum static pressure and the static pressure of the effective air volume section can be improved.

[0055] In step S122, the first radius of the first circular arc line AB is determined based on the diameter Φ of the fan impeller 210 and the maximum opening H0 of the fan volute 300, and the first circular arc line AB is drawn according to the first center O1 and the first radius.

[0056] In the formula, the first radius is equal to the distance between the first center O1 and the first intersection point A1; the first intersection point A1 is located on the negative half of the X-axis, and the distance between the first intersection point A1 and the center O of the fan impeller 210 is equal to the sum of the radius Φ / 2 of the fan impeller 210 and the maximum opening H0 of the fan volute 300.

[0057] In step S123, the second radius of the second circular arc line BC is determined based on the first circular arc line AB, and the second circular arc line BC is drawn according to the second center O2 and the second radius.

[0058] In the formula, the second radius is equal to the distance between the second center O2 and the second intersection point B, and the second intersection point B is the intersection point of the first circular arc line AB and the negative half of the Y-axis; during the drawing process, the first circular arc line AB intersects with the negative half of the Y-axis counterclockwise based on the first center O1 and the first radius, and the second intersection point B is obtained.

[0059] In step S124, the third radius of the third circular arc line CD is determined based on the second circular arc line BC, and the third circular arc line CD is drawn according to the third center O3 and the third radius.

[0060] In the formula, the third radius is equal to the distance between the third center O3 and the third intersection point C, and the third intersection point C is the intersection point of the second circular arc line BC and the positive half of the X-axis. During the drawing process, the second circular arc line BC intersects with the positive half of the X-axis counterclockwise based on the second center O2 and the second radius, and the third intersection point C is obtained.

[0061] Step S125, determining a fourth radius of the fourth circular arc DE based on the third circular arc CD, and drawing the fourth circular arc DE according to the fourth center O4 and the fourth radius.

[0062] wherein the fourth radius is equal to the distance between the fourth center O4 and the fourth intersection point D, and the fourth intersection point D is the intersection point of the third circular arc CD and the positive half-axis of Y-axis. In the drawing process, the third circular arc CD is drawn to intersect with the positive half-axis of Y-axis based on the third center O3 and the third radius counterclockwise, so that the fourth intersection point D is obtained.

[0063] Please refer to Figure 9 As another embodiment of the above step S121, the first rectangle, the second rectangle, the third rectangle and the fourth rectangle can be drawn based on the center O of the fan impeller 210 and the maximum opening H0 of the fan volute 300.

[0064] The first rectangle is located in the first quadrant, and the lengths of the two adjacent sides of the first rectangle are a1 and a2, wherein a1 is the horizontal side of the first rectangle, which is located on the positive half-axis of X-axis or parallel to the X-axis, and a2 is the vertical side of the first rectangle, which is located on the positive half-axis of Y-axis or parallel to the Y-axis; the second rectangle is located in the fourth quadrant, and the lengths of the two adjacent sides of the second rectangle are b1 and b2, wherein b1 is the vertical side of the second rectangle, which is located on the negative half-axis of Y-axis or parallel to the Y-axis, and b2 is the horizontal side of the second rectangle, which is located on the positive half-axis of X-axis or parallel to the X-axis; the third rectangle is located in the third quadrant, and the lengths of the two adjacent sides of the third rectangle are c1 and c2, wherein c1 is the vertical side of the third rectangle, which is located on the negative half-axis of Y-axis or parallel to the Y-axis, and c2 is the horizontal side of the third rectangle, which is located on the negative half-axis of X-axis or parallel to the X-axis; the fourth rectangle is located in the second quadrant, and the lengths of the two adjacent sides of the fourth rectangle are d1 and d2, wherein d1 is the vertical side of the fourth rectangle, which is located on the positive half-axis of Y-axis or parallel to the Y-axis, and d2 is the horizontal side of the fourth rectangle, which is located on the negative half-axis of X-axis or parallel to the X-axis.

[0065] wherein |b1-a1|>|c1-b1|>|d1-c1|, and a1=(2-2.5)a2, b1=(0.75-1)b2, c1=(1.4-2)c2, d1=(0.8-1)d2.

[0066] The center O of the fan impeller 210 and the first center O1 are located at the opposite corners of the fourth rectangle, the center O of the fan impeller 210 and the second center O2 are located at the opposite corners of the third rectangle, the center O of the fan impeller 210 and the third center O3 are located at the opposite corners of the second rectangle, and the center O of the fan impeller 210 and the fourth center O4 are located at the opposite corners of the first rectangle.

[0067] The specific values of the side lengths a1, b1, c1 and d1 are determined according to the maximum opening degree H0 of the fan volute 300. For example, a1=0.15H0, b1=0.1166H0, c1=0.1333H0 and d1=0.14H0, and in this case, |b1-a1|=0.0334H0, |c1-b1|=0.0167H0 and |d1-c1|=0.0067H0, satisfying the relationship |b1-a1|>|c1-b1|>|d1-c1|. In this embodiment, the first, second, third and fourth circular arcs AB, BC, CD and DE have different curvatures, and |b1-a1|>|c1-b1|>|d1-c1|, so that the volute profile 340 has different opening degrees in different quadrants, thereby increasing the volume of the fan volute 300.

[0068] The specific values of the side lengths a2, b2, c2 and d2 can be adjusted according to the width and height of the fan frame 110, thereby adjusting the second, third, fourth maximum opening degrees H2, H3 and H4 and the volute tongue gap t. For example, a1 can be equal to 2a2, 2.2a2, 2.3a2 or 2.5a2, b1 can be equal to 0.75b2, 0.85b2, 0.9b2 or b2, c1 can be equal to 1.4c2, 1.6c2, 1.8c2 or 2c2, and d1 can be equal to 0.8d2, 0.9d2, 0.95d2 or d2.

[0069] Preferably, by adjusting the specific values of the side lengths a2, b2, c2 and d2, the first and third maximum opening degrees H1 and H3 satisfy the relationship 2.5≤H1 / H3≤3, for example, H1 / H3 can be equal to 2.5, 2.7, 2.8 or 3, the fourth maximum opening degree H4 and the volute tongue gap t satisfy the relationship 1≤H4 / t≤1.3, for example, H4 / t can be equal to 1, 1.2, 1.25 or 1.3, and the volute tongue gap t and the diameter Φ of the fan impeller 210 satisfy the relationship 0.03≤t / Φ≤0.05, for example, t / Φ can be equal to 0.03, 0.04, 0.045 or 0.05. In this way, the flow rate in the volute can be greatly improved, and the maximum static pressure and the static pressure in the effective air volume section can be greatly improved. In addition, during drawing, the volute profile 340 can be enlarged or reduced in proportion to the four circular arcs, thereby increasing the flexibility of the design.

[0070] The volute profile 340 generation method provided by the embodiment of the present application firstly acquires the maximum opening degree H0 of the fan volute 300, and then sequentially draws the first circular arc line AB, the second circular arc line BC, the third circular arc line CD and the fourth circular arc line DE based on the maximum opening degree H0 of the fan volute 300, that is, draws the volute profile 340 in the counterclockwise direction, which can fully utilize the width of the fan rack 110 to increase the volume of the volute while ensuring a certain gap between the fan volute 300 and the fan rack 110.

[0071] Further, Figure 10 A comparison diagram of the volute profiles of the forward design and the reverse design is shown, wherein the dashed line is the volute profile drawn by the related art using the forward design, and the solid line is the volute profile drawn by the present application using the reverse design. Figure 10 As shown, the first circular arc line AB based on the same radian, the fan impeller based on the same reference, and the same absolute value of the second-order change rate (that is, the values of |a-b|, |b-c| and |c-d| in the forward design and the values of |a-b|, |b-c| and |c-d| in the reverse design are all equal to the same numerical value), the volute profile drawn by the reverse design has a smaller reduction degree of the radius of the volute profile, and it can be known that the volute profile drawn by the forward design is located in the volute profile drawn by the reverse design, the volute profile drawn by the reverse design has a larger volume, greatly improves the maximum static pressure, and the diameter of the fan impeller can be larger, which can reduce the speed and noise while improving the user experience.

[0072] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments made according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for generating the volute profile of a wind turbine volute, characterized in that, The method includes: Obtain the maximum opening degree of the fan casing; Based on the maximum opening of the wind turbine volute, a first arc, a second arc, a third arc, and a fourth arc are drawn sequentially; wherein, the first arc, the second arc, the third arc, and the fourth arc are smoothly connected sequentially; the first arc has a first maximum arc opening, and the first maximum arc opening is equal to the maximum opening of the wind turbine volute; the second arc has a second maximum arc opening; the third arc has a third maximum arc opening; the fourth arc has a fourth maximum arc opening; and the maximum arc openings of the first, second, third, and fourth arcs decrease sequentially. The process of obtaining the maximum opening degree of the wind turbine volute includes: Determine the relative positional relationship between the fan impeller and the fan frame; The maximum opening of the fan casing is determined based on the diameter of the fan impeller and the width of the fan frame; The step of drawing the first, second, third, and fourth arcs sequentially based on the maximum opening of the wind turbine volute includes: The first center of the first arc, the second center of the second arc, the third center of the third arc, and the fourth center of the fourth arc are determined based on the maximum opening of the wind turbine volute. The first radius of the first arc is determined based on the diameter of the wind turbine impeller and the maximum opening of the wind turbine volute, and the first arc is drawn according to the first center and the first radius. The second radius of the second arc is determined based on the first arc, and the second arc is drawn according to the second center and the second radius; The third radius of the third arc is determined based on the second arc, and the third arc is drawn according to the third center and the third radius; The fourth radius of the fourth arc is determined based on the third arc, and the fourth arc is drawn according to the fourth center and the fourth radius.

2. The method according to claim 1, characterized in that, The step of determining the first center of the first arc, the second center of the second arc, the third center of the third arc, and the fourth center of the fourth arc based on the maximum opening of the wind turbine volute includes: Based on the center of the wind turbine impeller and the maximum opening of the wind turbine volute, draw a first rectangle, a second rectangle, a third rectangle, and a fourth rectangle; the lengths of adjacent sides of the first rectangle are a1 and a2, the lengths of adjacent sides of the second rectangle are b1 and b2, the lengths of adjacent sides of the third rectangle are c1 and c2, and the lengths of adjacent sides of the fourth rectangle are d1 and d2; wherein, |b1-a1|>|c1-b1|>|d1-c1|, and a1=(2~2.5)a2, b1=(0.75~1)b2, c1=(1.4~2)c2, d1=(0.8~1)d2; The center of the fan impeller and the center of the first circle are respectively located at opposite vertices of the fourth rectangle; the center of the fan impeller and the center of the second circle are respectively located at opposite vertices of the third rectangle; the center of the fan impeller and the center of the third circle are respectively located at opposite vertices of the second rectangle; and the center of the fan impeller and the center of the fourth circle are respectively located at opposite vertices of the first rectangle.

3. The method according to claim 2, characterized in that, The maximum opening H1 of the first arc and the maximum opening H3 of the third arc satisfy the following relationship: 2.5≤H1 / H3≤3; the maximum opening H4 of the fourth arc and the volute tongue gap t satisfy the following relationship: 1≤H4 / t≤1.

3.

4. The method according to any one of claims 1-3, characterized in that, The angle β between the starting point of the first arc and the center of the fan impeller and the horizontal reference line satisfies the following relationship: 0°≤β≤24°.

5. The method according to any one of claims 1-3, characterized in that, The volute clearance t and the impeller diameter Φ of the fan satisfy the following relationship: 0.03≤t / Φ≤0.

05.

6. A fan casing, characterized in that, It includes a first cover plate, a second cover plate, and a surrounding plate. The first cover plate and the second cover plate are disposed opposite to each other. The surrounding plate is connected between the first cover plate and the second cover plate. The outline of the inner surface of the surrounding plate is a volute profile, which is generated by the method according to any one of claims 1-5.

7. A centrifugal fan, characterized in that, It includes a fan impeller and a fan volute as described in claim 6, wherein the fan impeller is installed inside the fan volute.

8. A range hood, characterized in that, It includes a fan frame and a centrifugal fan as described in claim 7, wherein the centrifugal fan is installed within the fan frame.

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