Design method of volute, volute, volute components and range hood

Abstract

This invention discloses a design method for a volute, a volute itself, a volute assembly, and a range hood. The design method includes: determining the base circle diameter of the volute and drawing the base circle; drawing N center lines based on the center of the base circle, each center line passing through the center of the circle, and the angle between any two adjacent center lines being a preset angle; selecting one center line as the 0° center line, and determining the position of the first main spiral control point on the 0° center line, setting a second main spiral control point on the 90° center line, and setting a third main spiral control point on the 270° center line; determining the position of the spiral control points on the remaining center lines based on the spiral radii of the spiral control points on the N center lines forming a second-order arithmetic sequence; and obtaining a complete spiral by connecting the positions of the N spiral control points using spline curves. This volute design method is simple and reliable, and can quickly design volutes suitable for large airflow conditions.

Description

Technical Field

[0001] This invention relates to the field of range hoods, and particularly to a design method for a volute, a volute, a volute assembly, and a range hood. Background Technology

[0002] The function of the volute in a range hood is to guide the gas leaving the impeller to the volute outlet and convert some of the gas's kinetic energy into static pressure. Conventional range hood volute designs are often based on a standard spiral design method, and then the spiral is modified to obtain a volute with a better profile.

[0003] The volute profile designed based on the standard spiral is usually ineffective under high airflow conditions, so it often needs to be redesigned, i.e., volute modification. To find a better solution, volute modification often requires designing multiple schemes for comparison and verification analysis, which consumes a lot of time and effort. At the same time, the modified profile often has uneven transitions in some modified sections, which can cause unstable gas flow or vortex problems inside the volute.

[0004] Traditional design of spiral volutes typically follows these assumptions: the airflow within the volute is steady-state, therefore the streamlines of the fluid particles are their trajectories; the fluid flows uniformly along the entire impeller circumference, meaning the flow rate at different cross-sections of the volute is proportional to the angle between that cross-section and the initial cross-section of the volute. When the effect of friction is ignored, according to the principle of constant angular momentum: The entire cross-section of the volute is filled with effective airflow. Finally, the radius of motion of the fluid particle can be obtained. The above indicates that the trajectory of a fluid particle is a logarithmic helix. Typically, this is... Taylor expansion, simplifying by taking the first two terms of the expansion, yields the original expression as follows: In the form of, Therefore, by comparing the above equations, we can see that the simplified helix equation ( ) and the original equation ( The simplified spiral equation only shares the same trend, both being monotonically increasing. However, it cannot fit the original equation well. The reason is that the radius change in the simplified spiral equation conforms to a first-order equation, i.e., y=ax+b, where each radius increase is a fixed coefficient (a) before the variable. In contrast, the original equation exhibits an exponential growth pattern in the radius, meaning... The form is a curve with gradually increasing curvature, meaning the value increases with each increase in radius. Therefore, to better fit the original helix equation, the order of the helix radius variation equation needs to be greater than 1, but generally should not exceed 3. This is because if the helix opening is too large, the fluid inside the volute may not be fully filled, thus reducing efficiency. In practice, only the second-order equation is often used when applying the helix radius variation equation, because the form of the second-order equation corresponds precisely to a second-order arithmetic sequence in the helix radius variation; other orders are more difficult to derive. The following example uses a second-order helix radius variation equation.

[0005] The specific technical solution is as follows:

[0006] The radius of the helix should meet the following requirements. The three coefficients a, b, and c can be determined by the user, but they must meet the size limitations of the enclosure. However, this method often fails to meet design requirements well because the range of a and b is too large to quickly determine suitable parameters.

[0007] Therefore, the existing design methods for volutes cannot quickly design volutes that perform well under large air volume conditions. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defect of the existing volute design method that cannot quickly design a volute with good performance under large air volume conditions, and to provide a volute design method, volute, volute assembly and range hood in the field of range hoods.

[0009] The present invention solves the above-mentioned technical problems through the following technical solution:

[0010] A method for designing a volute, the method comprising the following steps:

[0011] S1. Determine the base circle diameter of the volute and draw the base circle;

[0012] S2. Based on the center of the base circle, draw N center lines spaced apart along the circumference. Each center line passes through the center of the circle, and the angle between any two adjacent center lines is a preset angle α, where N is the ratio of 360° to the preset angle α.

[0013] S3. Select any center line as the 0° center line, and determine the position of the first principal helix control point on the 0° center line. The distance from the first principal helix control point to the center of the circle is the helix radius R of the first principal helix control point. 0° And the helix radius R of the first main helix control point 0° Greater than the radius of the volute;

[0014] S4. On both sides of the 0° center line, a second main spiral control point is set on a 90° center line at a 90° angle to the 0° center line, and a third main spiral control point is set on a 270° center line at a 270° angle to the 0° center line. The sum of the spiral radii of the second and third main spiral control points is less than the maximum cross-sectional dimension of the fan frame encapsulating the volute. The spiral radii of the second and third main spiral control points are obtained according to the specifications of the fan frame.

[0015] S5. Based on the spiral radii of the spiral control points on the N center lines, a second-order arithmetic sequence is formed, and the general term formula of the second-order arithmetic sequence is used... Determine the positions of the spiral control points on the remaining center lines, where b1 = a2 - a1, d is the difference of a second-order arithmetic sequence, and d = b2 - b1 = a1 + a3 - 2 * a2, n takes a value between 1 and N, R0° = a1, and n of either the spiral radius of the second main spiral control point or the spiral radius of the third main spiral control point takes a value of The other n takes the value of ;

[0016] S6. Based on the positions of N spiral control points, a complete spiral is obtained by connecting spline curves.

[0017] In this scheme, the helix radii corresponding to each point on the complete helix of the volute form a second-order arithmetic sequence, and the known initial angle of the volute tongue is used. and the space between the cochlear tongues The three main spiral control points are selected to form a second-order arithmetic sequence corresponding to the volute. The position of each spiral control point is determined based on the second-order arithmetic sequence. The volute obtained in this way can be well applied to large air volume conditions. Moreover, this volute design method is simple and reliable, and can design the volute relatively quickly.

[0018] Preferably, the preset angle is between 15° and 45°.

[0019] In this scheme, the above settings ensure both the reliability of the volute design and its relatively rapid implementation, thus achieving a good balance between reliability and efficiency. If the preset angle is too large, the number of center lines and corresponding helical control points will be too small, potentially reducing the reliability or accuracy of the volute design. Conversely, if the preset angle is too small, the number of center lines and corresponding helical control points will be too large, which can further improve the reliability or accuracy of the volute design, but also makes the design process more complex and hinders rapid completion.

[0020] Preferably, the preset angle is 30°, the helix radius of the second principal helix control point is a4, and the helix radius of the third principal helix control point is a. 10 ;

[0021] The conversion yields: , .

[0022] In this design, the preset angle is set to 30°, which helps to further balance the reliability and efficiency of the volute design.

[0023] Preferably, in step S1, the diameter of the base circle is determined based on the diameter of the impeller installed in the volute, and the diameter of the base circle is not less than the diameter of the impeller.

[0024] In this scheme, the diameter of the base circle is set based on the positional relationship between the impeller and the volute. The method for obtaining the diameter of the base circle is simple and reliable.

[0025] Preferably, between step S5 and step S6, the design method further includes the following step:

[0026] Step S5′: Determine the cochlear tongue initiation angle and cochlear gap Wherein, the cochlear tongue is adjacent to the 0° centerline, and the cochlear tongue starting angle is... and cochlear gap One is specified, and the other is based on formula R. 0° = get.

[0027] In this scheme, the volute tongue is positioned near the 0° centerline, and based on the positional relationship between the volute tongue and the 0° centerline, and referring to the above formula, the starting angle of the volute tongue is set. Cochlear tongue interspace By establishing a correlation between the spiral radius R0° and the control point of the first main spiral, the starting angle of the volute tongue can be determined relatively conveniently and reliably. or the space between the cochlear tongues .

[0028] Preferably, the fan frame has a length in the left-right direction and a height in the up-down direction, and the length of the fan frame is greater than its height;

[0029] In step S4, the maximum cross-sectional dimension of the wind turbine frame is the length.

[0030] In this scheme, the spiral radius of the second main spiral control point and the sum of the spiral radii of the third main spiral control point are set based on the positional relationship between the volute and the wind turbine frame, according to the length of the wind turbine frame. The setting method is simple and reliable.

[0031] Preferably, the sum of the helix radius of the second main helix control point and the helix radius of the third main helix control point is smaller than the length, and the difference is between 10 and 20 mm.

[0032] In this solution, the above-mentioned configuration ensures that the volute is encapsulated within the fan frame while also enabling the volute design to meet optimal performance requirements.

[0033] The present invention also provides a volute, which is designed using the above-described volute design method.

[0034] The present invention also provides a volute assembly including an impeller, the volute assembly further including the aforementioned volute having mounting holes for mounting the impeller.

[0035] The present invention also provides a range hood, including a fan frame, and the range hood further includes the aforementioned volute assembly, which is installed inside the fan frame.

[0036] The positive and progressive effects of this invention are as follows:

[0037] In this volute design method, a second-order arithmetic sequence is formed based on the helix radii corresponding to each point on the complete helix of the volute. This sequence is then used in conjunction with the known initial angle of the volute tongue. and the space between the cochlear tongues The three main spiral control points are selected to form a second-order arithmetic sequence corresponding to the volute. The position of each spiral control point is determined based on the second-order arithmetic sequence. The volute obtained in this way can be well applied to large air volume conditions. Moreover, this volute design method is simple and reliable, and can design the volute relatively quickly. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating a preferred embodiment of the design method for a volute casing according to the present invention.

[0039] Figure 2 This is a three-dimensional structural diagram of the volute shell according to a preferred embodiment of the present invention.

[0040] Figure 3 This is a front view of the volute casing according to a preferred embodiment of the present invention.

[0041] Figure 4 This is a schematic diagram illustrating the design process of the volute casing according to a preferred embodiment of the present invention.

[0042] Figure 5 This is a partial structural diagram of a range hood according to a preferred embodiment of the present invention, showing the volute and the fan frame.

[0043] Figure 6This is a schematic diagram of another part of the structure of a range hood according to a preferred embodiment of the present invention, showing the volute and the fan frame.

[0044] Explanation of reference numerals in the attached figures:

[0045] 10. Snail shell

[0046] 101 mounting holes

[0047] 20 wind turbine racks Detailed Implementation

[0048] 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 described herein.

[0049] like Figures 1 to 6 As shown, this embodiment provides a design method for a volute 10, and also provides a volute 10 designed using this method. Further, this embodiment provides a volute assembly, which includes an impeller (not shown) and the aforementioned volute 10, the volute 10 having a mounting hole 101 for mounting the impeller. Even further, the present invention provides a range hood, which includes a fan frame 20 and the aforementioned volute assembly, the volute assembly being installed within the fan frame 20.

[0050] Reference Figure 1 and Figure 4 To understand this, the design method includes the following steps:

[0051] Step S100: Determine the base circle diameter of the volute 10 (e.g., Figure 4 (As shown in A) and draw the base circle;

[0052] Step S200: Based on the center of the base circle, draw N center lines spaced apart along the circumference. Each center line passes through the center of the circle, and the angle between any two adjacent center lines is a preset angle α, where N is the ratio of 360° to the preset angle α.

[0053] Step S300: Select any center line as the 0° center line, and determine the position of the first principal helix control point on the 0° center line. The distance from the first principal helix control point to the center of the circle is the helix radius R of the first principal helix control point. 0° And the helix radius R at the first principal helix control point 0° Greater than the radius of the volute;

[0054] Step S400: On both sides of the 0° center line, a second main spiral control point is set on the 90° center line at a 90° angle to the 0° center line, and a third main spiral control point is set on the 270° center line at a 270° angle to the 0° center line. The sum of the spiral radii of the second and third main spiral control points is less than the maximum cross-sectional dimension of the fan frame 20 of the encapsulated volute 10. The spiral radii of the second and third main spiral control points are obtained according to the specifications of the fan frame 20.

[0055] Step S500: Based on the spiral radii of the spiral control points on the N center lines, a second-order arithmetic sequence is formed, and the general term formula of the second-order arithmetic sequence is applied. Determine the positions of the spiral control points on the remaining center lines, where b1 = a2 - a1, d is the difference of a second-order arithmetic sequence, and d = b2 - b1 = a1 + a3 - 2 * a2, n takes values ​​between 1 and N, and R 0° = a1, where n is one of the helical radii at the control points of the second and third principal helical lines. The other n takes the value of ;

[0056] Step S600: Based on the positions of the N spiral control points, a complete spiral is obtained by connecting spline curves.

[0057] In this embodiment, the helix radii corresponding to each point on the complete helix of the volute 10 form a second-order arithmetic sequence, and the known initial angle of the volute tongue is used. and the space between the cochlear tongues The three main spiral control points are selected to form a second-order arithmetic sequence corresponding to the volute 10. The position of each spiral control point is determined based on the second-order arithmetic sequence. The volute 10 obtained in this way can be well applied to large air volume conditions. Moreover, this volute 10 design method is simple and reliable, and the volute 10 can be designed relatively quickly.

[0058] As a preferred setting, the preset angle is between 15° and 45°.

[0059] This configuration ensures both the reliability of the volute 10 design and its relatively rapid implementation, thus achieving a good balance between reliability and efficiency. If the preset angle is too large, the number of center lines and corresponding helical control points will be too small, potentially reducing the reliability or accuracy of the volute 10 design. Conversely, if the preset angle is too small, the number of center lines and corresponding helical control points will be too large, further improving the reliability and accuracy of the volute 10 design. However, this also makes the design process more complex and hinders rapid completion.

[0060] In this specific embodiment, the preset angle α is 30°. Correspondingly, N is 12. Figure 4 The diagram schematically illustrates the positions of 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, and 330°. The helix radius of the second principal helix control point is a4, and the helix radius of the third principal helix control point is a. 10 ;

[0061] The conversion yields: , .

[0062] Here, setting the preset angle to 30° helps to further balance the reliability and efficiency of the volute 10 design.

[0063] In this context, d is obtained by substituting n=1, n=4, and n=10 into the general term formula of a second-order arithmetic sequence and converting the values. The specific calculation or conversion process is as follows.

[0064]

[0065]

[0066]

[0067] Furthermore, in step S100, the diameter of the base circle is determined based on the diameter of the impeller installed in the volute 10, and the diameter of the base circle is not less than the diameter of the impeller.

[0068] The diameter of the base circle is set by considering the positional relationship between the impeller and the volute 10. The method for obtaining the diameter of the base circle is simple and reliable.

[0069] Furthermore, between step S500 and step S600, the design method further includes the following steps:

[0070] Step S500': Determine the cochlear tongue initiation angle. and cochlear gap Among them, the cochlear tongue is adjacent to the 0° center line, and the cochlear tongue initial angle is... and cochlear gap One is specified, and the other is based on formula R. 0° = get.

[0071] Here, the volute tongue is positioned near the 0° centerline, and based on the positional relationship between the volute tongue and the 0° centerline, and referring to the formula above, the starting angle of the volute tongue is set. Cochlear tongue interspace By establishing a correlation between the spiral radius R0° and the control point of the first main spiral, the starting angle of the volute tongue can be determined relatively conveniently and reliably. or the space between the cochlear tongues .

[0072] It should be noted that, regarding the cochlear tongue origin angle and cochlear gap The one specified in the above can be specified in any step prior to step S500 in other alternative embodiments.

[0073] like Figure 5 and Figure 6 As shown, the wind turbine frame 20 has a length in the left-right direction and a height in the up-down direction, and the length of the wind turbine frame 20 is greater than its height.

[0074] In step S400, the maximum cross-sectional dimension of the wind turbine frame 20 is its length.

[0075] Based on the positional relationship between the volute 10 and the fan frame 20, the sum of the spiral radii of the second main spiral control point and the spiral radii of the third main spiral control point is set according to the length of the fan frame 20. The setting method is simple and reliable.

[0076] Furthermore, the sum of the helix radii of the second and third main helix control points is smaller than the length, and the difference is between 10 and 20 mm.

[0077] This configuration ensures that the volute 10 is encapsulated within the fan frame 20, while also allowing the design of the volute 10 to meet optimal performance requirements.

[0078] The following example illustrates the process of designing a volute using the volute design method described in this application:

[0079] First, the given dimensions of the wind turbine frame are 330*280*480 mm (length*width*height).

[0080] Then, based on the dimensions of the wind turbine frame, and using experience, the impeller diameter is chosen to be 220mm, and correspondingly, the base circle of the volute is determined.

[0081] Next, the control point value at 0° is pre-selected as 125mm, i.e., a1=125, and the initial angle of the volute tongue is 15°;

[0082] Finally, based on the above conditions, the values ​​of parameters d and b are determined according to the 90° and 270° design points. Here, a4 + a10 < 330, i.e., 2a1 + 12b + 39d < 330. The value of a1 is known and further simplified to 12b + 39d < 80. d has a significant impact on the overall value increase. To ensure the volute size is not too large and to reserve a certain installation space (minimum 7mm on one side), d is initially set to 1 (an integer for simplified calculation), and b can be set to 2. Then the position of each control point can be calculated. For example, a1 = 125, a2 = 127, a3 = 130, a4 = 134, a5 = 139, a6 = 145, a7 = 152, a8 = 160, a9 = 169, a10 = 179, a11 = 190, a12 = 202. After the initial design of the volute using this method, the distance between the control points can still be fine-tuned to adjust the entire curve and thus optimize the volute. Specifically, in this embodiment, the helix radius of the first main helix control point is 125mm, the helix radius of the second main helix control point is 134mm, and the helix radius of the third main helix control point is 179mm.

[0083] In this example, the helix radius R based on the first principal helix control point 0° With the initial angle of the cochlear tongue and the space between the cochlear tongues The formula R satisfies 0° = Based on a1=125 and the initial angle of the cochlear tongue is 15°, the cochlear tongue gap can be calculated. It is 124.5mm.

[0084] 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 designing a volute, characterized in that, The design method includes the following steps: S1. Determine the base circle diameter of the volute and draw the base circle; S2. Based on the center of the base circle, draw N center lines spaced apart along the circumference. Each center line passes through the center of the circle, and the angle between any two adjacent center lines is a preset angle α, where N is the ratio of 360° to the preset angle α. S3. Select any center line as the 0° center line, and determine the position of the first principal helix control point on the 0° center line. The distance from the first principal helix control point to the center of the circle is the helix radius R of the first principal helix control point. 0° And the helix radius R of the first main helix control point 0° Greater than the radius of the volute; S4. On both sides of the 0° center line, a second main spiral control point is set on a 90° center line at a 90° angle to the 0° center line, and a third main spiral control point is set on a 270° center line at a 270° angle to the 0° center line. The sum of the spiral radii of the second and third main spiral control points is less than the maximum cross-sectional dimension of the fan frame encapsulating the volute. The spiral radii of the second and third main spiral control points are obtained according to the specifications of the fan frame. S5. Based on the spiral radii of the spiral control points on the N center lines, a second-order arithmetic sequence is formed, and the general term formula of the second-order arithmetic sequence is used... Determine the positions of the spiral control points on the remaining center lines, where b1 = a2 - a1, d is the difference of a second-order arithmetic sequence, and d = b2 - b1 = a1 + a3 - 2 * a2, n takes a value between 1 and N, R0° = a1, and n of either the spiral radius of the second main spiral control point or the spiral radius of the third main spiral control point takes a value of The other n takes the value of ; S6. Based on the positions of N spiral control points, a complete spiral is obtained by connecting spline curves.

2. The design method of the volute as described in claim 1, characterized in that, The preset angle is between 15° and 45°.

3. The design method of the volute as described in claim 2, characterized in that, The preset angle is 30°, the helix radius of the second main helix control point is a4, and the helix radius of the third main helix control point is a. 10 ; The conversion yields: , .

4. The design method of the volute as described in claim 1, characterized in that, In step S1, the diameter of the base circle is determined based on the diameter of the impeller installed in the volute, and the diameter of the base circle is not less than the diameter of the impeller.

5. The design method of the volute as described in claim 1, characterized in that, Between step S5 and step S6, the design method further includes the following steps: Step S5′: Determine the cochlear tongue initiation angle and cochlear gap Wherein, the cochlear tongue is adjacent to the 0° centerline, and the cochlear tongue starting angle is... and cochlear gap One is specified, and the other is based on formula R. 0° = get.

6. The design method of the volute as described in any one of claims 1-5, characterized in that, The wind turbine frame has a length in the left-right direction and a height in the up-down direction, and the length of the wind turbine frame is greater than its height. In step S4, the maximum cross-sectional dimension of the wind turbine frame is the length.

7. The design method of the volute as described in claim 6, characterized in that, The sum of the helix radius of the second main helix control point and the helix radius of the third main helix control point is smaller than the length, and the difference is between 10 and 20 mm.

8. A volute, characterized in that, The volute is designed using the volute design method as described in any one of claims 1-7.

9. A volute assembly, comprising an impeller, characterized in that, The volute assembly further includes the volute as claimed in claim 8, the volute having mounting holes for mounting the impeller.

10. A range hood, comprising a fan frame, characterized in that, The range hood also includes the volute assembly as described in claim 9, the volute assembly being installed within the fan frame.

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