Test centrifugal fan volute and test centrifugal fan volute design method

Abstract

The present application relates to a centrifugal fan volute for testing and a design method for a centrifugal fan volute for testing. The centrifugal fan volute for testing includes a front cover, a rear cover and a plurality of adjustment mechanisms. Each adjustment mechanism includes an adjustment rod and two limit plates respectively sleeved and connected to the two ends of the adjustment rod. Through holes are respectively provided on the front cover and the rear cover. The limit plates are stopped at the outside of the through holes. The adjustment rod is movably passed through the through holes, and a sealing gasket is provided between the adjustment rod and the hole wall of the through hole. The thickness of the limit plate is B, and wherein F Z is the friction force between the sealing gasket and the adjusting rod when the adjusting rod moves along the through hole; L is the distance between the two limit plates; [σ n ] is the allowable compressive stress of the regulating rod; S n The test centrifugal fan volute and the test centrifugal fan volute provided by the present application are conducive to reducing the interference of the limit plate on the external flow field under the condition of meeting the structural strength of the adjustment mechanism.

Description

Technical Field

[0001] The present application relates to the field of fan technology, and in particular to a centrifugal fan volute for testing and a design method for a centrifugal fan volute for testing. Background Art

[0002] During the testing process of traditional centrifugal fans, the design and manufacture of the volute structure face a significant challenge. Whenever test data reveals design deficiencies and a new design solution needs to be tried, a completely new volute needs to be machined. This results in long waiting times for proofing and significantly increases the length of the testing cycle. This not only affects the product's time to market but also significantly increases development costs. Therefore, it is necessary to design a centrifugal fan volute with adjustable profile for testing to avoid the need to machine a completely new volute multiple times during the testing process.

[0003] A common centrifugal fan volute used for testing includes a front cover plate, a rear cover plate, an annular wall, and multiple adjustment mechanisms. The annular wall is movably clamped between the front and rear cover plates. The multiple adjustment mechanisms are distributed along the circumference of the annular wall to adjust the contour of the annular wall. Specifically, each adjustment mechanism includes an adjustment rod and two limit plates. The two limit plates are respectively stopped on the outer sides of the front cover and the rear cover facing away from each other. One end of the adjustment rod passes through the front cover and is connected to one of the limit plates, and the other end of the adjustment rod passes through the rear cover and is connected to the other limit plate. The adjustment rod stops on the outer side of the annular wall. As the limit plates rotate to different positions, the position of the adjustment rod is adjusted, thereby adjusting the contour of the annular wall.

[0004] When applying the above solution, the thicker the limit plate, the higher the structural strength of the adjustment mechanism. However, the thicker the limit plate, the greater the impact on the flow field outside the centrifugal fan volute, which in turn affects the accuracy of centrifugal fan volute testing. Therefore, how to design an adjustment mechanism for a centrifugal fan volute that ensures the strength of the adjustment mechanism while reducing the impact on the flow field outside the centrifugal fan volute is a problem that needs to be solved. Summary of the Invention

[0005] Based on this, it is necessary to provide a test centrifugal fan volute and a test centrifugal fan volute design method that can solve the above problems.

[0006] A centrifugal fan volute for testing, comprising a front cover, a rear cover, and a plurality of adjustment mechanisms, each of which comprises an adjustment rod and two limit plates respectively sleeved and connected to both ends of the adjustment rod, a through hole being respectively provided on the front cover and the rear cover, the limit plates being stopped at the outside of the through hole, the adjustment rod being movably passed through the through hole, and a sealing gasket being provided between the adjustment rod and the hole wall of the through hole, the thickness of the limit plate being B, and B ≥ Among them, F Zis the friction force between the sealing gasket and the adjusting rod when the adjusting rod moves along the through hole; L is the distance between the two limit plates; [σ n ] is the allowable compressive stress of the regulating rod; S n is the contact area between the limit plate and the adjusting rod.

[0007] In one embodiment, the adjustment mechanism also includes a knob, a first matching position is provided on the knob, and a second matching position is provided on the limit plate; wherein, one of the first matching position and the second matching position is configured as a groove, and the other is configured as a boss, the groove and the boss are snap-connected, and can limit the relative rotation of the knob and the limit plate.

[0008] The present application also provides a method for designing a centrifugal fan volute for testing, the method for designing a centrifugal fan volute for testing is used to design the centrifugal fan volute for testing described in any one of the above embodiments, and the method for designing a centrifugal fan volute for testing comprises: obtaining F Z 、F n , L, B, and get Get S n , and the contact stress between the limit plate and the adjusting rod is obtained Get [σ n ], according to σ n ≤[σ n ], get L, B, S n With F z Satisfy between:

[0009] In one embodiment, the design method for a centrifugal fan volute for testing further includes: obtaining a friction coefficient μ between the adjusting rod and the sealing gasket, obtaining an extrusion force F between the adjusting rod and the sealing gasket, obtaining a load safety factor K1 between the adjusting rod and the sealing gasket, and obtaining F z =μ*K1*F; where, 0.3≤μ≤0.5; 3≤K1≤5.

[0010] In one embodiment, the method for designing a volute of a centrifugal fan for testing further includes: obtaining a design pressure σ1 between the adjusting rod and the sealing gasket, obtaining a contact area S between the adjusting rod and the sealing gasket m , and we get F=σ1*S m , where 4500Pa≤σ1≤7500Pa.

[0011] In one embodiment, the method for designing a volute of a centrifugal fan for testing further includes: obtaining a contact length L between the adjusting rod and the sealing gasket along the circumference of the adjusting rod. h , obtain the contact height H between the adjusting rod and the sealing gasket along the axial direction of the adjusting rod, and obtain S m =L h *H.

[0012] In one embodiment, the method for designing a volute of a centrifugal fan for testing further includes: obtaining the deformation amount Δ of the sealing gasket squeezed along the radial direction of the adjusting rod. M , obtain the diameter d of the adjusting rod, and obtain

[0013] In one embodiment, the design method for a centrifugal fan volute for testing further includes: obtaining the thickness M of the sealing gasket along the radial direction of the adjusting rod, obtaining the elastic modulus E of the sealing gasket, and obtaining Among them, 0.5mm≤M≤5mm.

[0014] In one embodiment, the design method for a centrifugal fan volute for testing further includes: obtaining a contact area correction coefficient K2 between the limit plate and the adjustment rod, and obtaining S n =K2*π*d*B, where

[0015] In one embodiment, the centrifugal fan volute further includes a knob, a first mating position extending radially thereof is provided on the knob, and a second mating position extending radially thereof is provided on the limiting plate; one of the first mating position and the second mating position is configured as a groove, and the other is configured as a boss, the first mating position can be engaged with the second mating position and limit the relative rotation of the knob and the limiting plate; the design method of the centrifugal fan volute for testing further includes: obtaining the radius R of the limiting plate, obtaining the height V=R*tanα of the second mating position along the axial direction of the limiting plate, and the height difference Δ between the thickness of the limiting plate and the second mating position H =BV=BR*tanα; if Δ H >2mm, the second matching position is configured as a groove; if Δ H ≤2mm, the second matching position is configured as a boss;

[0016] Wherein, α is the angle between the highest point or the lowest point of the second matching position and the edge of the limiting plate relative to the surface of the limiting plate along the axial direction of the limiting plate, and α≥5°.

[0017] Compared with the prior art, the test centrifugal fan volute and the test centrifugal fan volute design method provided by the present application are such that, in the process of the adjustment mechanism moving along the through hole to adjust the annular wall profile, the torque balance formula of the adjustment rod is: Therefore, we can get In addition, in order to ensure that the pressure resistance between the adjusting rod and the limit plate is met, a In this way, under the condition of satisfying the structural strength of the adjustment mechanism, the minimum value of the limit plate thickness B is obtained. This helps reduce the interference of the limiting plate on the external flow field. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of the structure of the centrifugal fan volute used in the test provided in this application;

[0020] Figure 2 A schematic diagram of the structure of the adjustment mechanism provided in this application;

[0021] Figure 3 A schematic diagram of the cooperation between the limit plate and the knob of one embodiment provided in this application;

[0022] Figure 4 A side view of a limiting plate according to one embodiment of the present application;

[0023] Figure 5 A schematic diagram of the force acting on the regulating mechanism provided in this application;

[0024] Figure 6 Schematic diagram of the adjustment rod and through hole provided in this application Figure 1 ;

[0025] Figure 7 Schematic diagram of the adjustment rod and through hole provided in this application Figure 2 .

[0026] Figure numerals: 100, test centrifugal fan volute; 10, adjustment mechanism; 11, adjustment rod; 12, limit plate; 121, second matching position; 13, knob; 131, first matching position; 20, front cover; 21, through hole; 22, convex shaft; 30, rear cover; 40, sealing gasket; 50, annular wall. DETAILED DESCRIPTION

[0027] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0028] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0030] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the relevant listed items.

[0032] See also Figures 1 to 6The present application provides a centrifugal fan volute for testing, which includes a plurality of adjustment mechanisms 10, a front cover 20, a rear cover 30 and an annular wall 50. The annular wall 50 is sandwiched between the front cover 20 and the rear cover 30, and the plurality of adjustment mechanisms 10 and the annular wall 50 are distributed circumferentially. Each adjustment mechanism 10 includes an adjustment rod 11 and two limit plates 12 respectively sleeved and connected to the two ends of the adjustment rod 11. A through hole 21 and a convex shaft 22 are respectively provided on the front cover 20 and the rear cover 30. The through hole 21 is configured as an arc hole extending axially along the convex shaft 22. The limit plate 12 stops at the outside of the through hole 21, and the adjustment rod 11 is movably passed through the through hole 21 and stopped at the outer periphery of the annular wall 50. A sealing gasket 40 is provided between the adjustment rod 11 and the hole wall of the through hole 21. The thickness B of the limit plate 12 is, and Among them, F Z is the friction force between the sealing gasket 40 and the adjusting rod 11 when the adjusting rod 11 follows the limiting plate 12 to rotate relative to the volute of the test centrifugal fan; L is the distance between the two limiting plates 12; [σ n ] is the allowable compressive stress of the adjusting rod 11; S n is the contact area between the limiting plate 12 and the adjusting rod 11.

[0033] It is understood that the two limiting plates 12 are used to fix the front cover 20, the annular wall 50, and the rear cover 30, and by rotating the limiting plates 12 around the convex shaft 22, the adjustment rod 11 moves along the through hole 21, thereby changing the position of the annular wall 50 to adjust the contour of the annular wall 50. In addition, when the adjustment mechanism 10 moves along the through hole 21 to adjust the contour of the annular wall 50, the torque balance formula of the adjustment rod is: Therefore, we can get In addition, in order to ensure that the pressure resistance between the adjusting rod 11 and the limiting plate 12 is met, a In this way, under the condition that the structural strength of the adjustment mechanism 10 is satisfied, the minimum value of the thickness B of the limit plate 12 is obtained.

[0034] See also Figure 2 and Figure 3The adjustment mechanism 10 also includes a knob 13, a first matching position 131 is provided on the knob 13, and a second matching position 121 is provided on the limit plate 12; wherein, one of the first matching position 131 and the second matching position 121 is configured as a groove, and the other is configured as a boss, the groove is connected to the boss by a snap-fit ​​connection, and can limit the relative rotation of the knob 13 and the limit plate 12. In the related structure, a longer exposed portion is formed by setting the two ends of the adjustment rod 11 to extend out of the surface of the limit plate 12 respectively, so that the user can apply a force to the adjustment rod 11 by holding the exposed portion of the adjustment rod 11, thereby moving the adjustment rod 11 along the through hole 21. However, this form is not only laborious to operate, but also the longer exposed portion of the adjustment rod 11 will cause greater interference to the large external flow field of the volute of the test centrifugal fan. In this embodiment, by setting the knob 13, it is more convenient and labor-saving to screw the limit plate 12 through the knob 13. Furthermore, since the knob 13 and the limiting plate 12 are configured as a split-type detachable structure, it is possible to avoid the knob 13 affecting the external flow field of the test centrifugal fan volute when the test centrifugal fan volute is tested.

[0035] To achieve a snap-fit ​​connection between the groove and the boss, and to prevent relative rotation between the knob 13 and the limiting plate 12, in one embodiment, the groove and the boss are each configured in a strip shape. Alternatively, in another embodiment, the cross-sections of the groove and the boss are each configured in a triangular, quadrilateral, pentagonal, or other polygonal shape. This is sufficient as long as relative rotation between the knob 13 and the limiting plate 12 can be prevented.

[0036] For example, in one embodiment, Figure 3 As shown, the second matching position 121 is configured as a groove, and the groove extends along the radial direction of the limiting plate 12 .

[0037] The present application also provides a method for designing a centrifugal fan volute for testing, which is used to design the centrifugal fan volute described in any of the above embodiments. Specifically, the method for designing a centrifugal fan volute for testing includes:

[0038] Step S1: Get F Z 、F n , L, B, and get

[0039] Step S2: Get S n , and the contact stress between the limit plate 12 and the adjusting rod 11 is obtained

[0040] Step S3, obtain [σ n ], according to σ n ≤[σ n ], get L, B, S n With Fz Satisfy between:

[0041] In step S1, according to the torque balance formula of the adjustment rod 11

[0042] get

[0043] In step S3, [σ n ] depends on the materials selected for the adjusting rod 11 and the limiting plate 12.

[0044] The following describes how to obtain F through step S4. Z process.

[0045] Step S41, obtain the friction coefficient μ between the adjusting rod 11 and the sealing gasket 40, obtain the extrusion force F between the adjusting rod 11 and the sealing gasket 40, obtain the load safety factor K1 between the adjusting rod 11 and the sealing gasket 40, and obtain F z =μ*1*F; where, 0.3≤μ≤0.5; 3≤K1≤5.

[0046] Step S42: Obtain the design pressure σ1 between the adjusting rod 11 and the sealing gasket 40, and obtain the contact area S between the adjusting rod 11 and the sealing gasket 40. m , and we get F=σ1* m , where 4500Pa≤σ1≤7500Pa.

[0047] It can be understood that in step S42, by setting F = σ1* m , substitute F z =μ*1*F, we can get F z =μ*1*1* m .

[0048] Step S43, please refer to Figure 6 and Figure 7 , obtain the contact length L between the adjusting rod 11 and the sealing gasket 40 along the circumference of the adjusting rod 11 h , obtain the contact height H between the adjusting rod 11 and the sealing gasket 40 along the axial direction of the adjusting rod 11, and obtain S m =L h *H.

[0049] It can be understood that, in step S43, by m =L h *Substitute H into F z =μ*1*1* m , we can get F z =μ*1*1*L h *H.

[0050] Step S44, please continue to refer to Figure 6 and Figure 7 , obtain the deformation Δ of the sealing gasket 40 squeezed along the radial direction of the adjusting rod 11 M , obtain the diameter d of the adjusting rod, and obtain

[0051] It is understandable that by Substitute into F z =μ*1*1*L h *H, we can get

[0052] Step S45: Obtain the thickness M of the radial seal along the adjusting rod 11, obtain the elastic modulus E of the seal 40, and obtain Among them, 0.5mm≤M≤5mm.

[0053] It should be noted that the elastic modulus E of the sealing gasket 40 depends on the material selected for the sealing gasket 40. It is understandable that in step S45, by Substitute into In, you can get

[0054] Next, step S5 is used to introduce how to obtain S n method.

[0055] Step S5: Obtain the contact area correction coefficient K2 between the limit plate 12 and the adjustment rod 11, and obtain S n =K2*π*d*B, where

[0056] It should be noted that there is no particular order between step S4 and step S5, and step S5 may be placed first and step S5 may be placed later; or step S4 may be placed first and step S5 may be placed later. n =K2*π*d*B and Substitute into Can get in,

[0057] Thus, in the actual design and testing process of the centrifugal fan volute, the values ​​of μ, σ1, H, K1, d, M, [σn] and K2 can be set according to the needs, so as to obtain the value of U, and then according to Get the minimum value of the thickness B of the corresponding limit plate 12

[0058] Next, please refer to Figure 4Through step S6, taking the first matching position 131 extending along the radial direction of the knob 13 and the second matching position 121 extending along the radial direction of the limiting plate 12 as an example, the design method of the boss or groove is introduced.

[0059] Step S6: Obtain the radius R of the limiting plate 12, and obtain the height V=R*tanα of the second matching position 121 along the axial direction of the limiting plate 12, and the height difference Δ between the thickness of the limiting plate 12 and the second matching position 121. H =BV=BR*tanα; if Δ H >2mm, the second matching position 121 is configured as a groove; if Δ H ≤2mm, the second fitting position 121 is configured as a boss; wherein, α is the angle between the highest point or the lowest point of the second fitting position 121 and the edge of the limiting plate 12 relative to the surface of the limiting plate 12 along the axial direction of the limiting plate 12, and α≥5°.

[0060] It is understandable that the smaller α is, the smaller the height of the groove and the boss that fits together. If the height of the groove and the boss that fits together is too small, the knob 13 and the limit plate 12 may slip during the process of turning the knob 13. Therefore, by setting α ≥ 5°, it is helpful to ensure that the groove and the boss are firmly connected together without slipping. In addition, by configuring the second fitting position 121 as a groove when BV> 2mm, it is helpful to reduce the thickness of the limit plate 12. By configuring the second fitting position 121 as a boss when BV≤ 2mm, it is helpful to ensure the structural strength of the limit plate 12.

[0061] For example, in one embodiment, the friction coefficient μ between the adjusting rod 11 and the sealing gasket is 0.5; the design pressure σ1 between the adjusting rod 11 and the sealing gasket 40 is 5000 Pa; the contact height H between the adjusting rod 11 and the sealing gasket 40 along the axial direction of the adjusting rod 11 is 5 mm; the load safety factor K1 between the adjusting rod 11 and the sealing gasket 40 is 4; the diameter d of the adjusting rod 11 is 10 mm; the thickness M of the sealing gasket 40 along the radial direction of the adjusting rod 11 is 2 mm; the allowable compressive stress of the adjusting rod 11 [σ n ]=100Mpa; the contact area correction coefficient K2 of the limit plate 12 and the adjustment rod 11 is 0.015; the distance L between the two limit plates 12 is 200mm. Then get That is, the minimum value of B is 7.59. At the same time, tests were conducted on a common volute without an adjustment mechanism and having the same profile, a rod-adjustable test volute adjusted by an adjustment rod, and a test centrifugal fan volute provided in this application. The test data are as follows.

[0062]

[0063] It can be understood from the above experiments that under the same maximum air volume conditions, the closer the thickness B of the centrifugal fan volute for testing provided in this application is to the minimum value of 7.59, the closer the noise situation in the semi-anechoic chamber is to that of an ordinary volute with the same profile.

[0064] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall be determined by the appended claims.

Claims

1. A centrifugal fan volute for testing, characterized in that: The test centrifugal fan volute comprises a front cover (20), a rear cover (30), an annular wall (50) and a plurality of adjustment mechanisms (10), wherein the annular wall (50) is clamped between the front cover (20) and the rear cover (30), and the plurality of adjustment mechanisms (10) are distributed along the circumference of the annular wall (50), and each of the adjustment mechanisms (10) comprises an adjustment rod (11) and two limit plates (12) respectively sleeved and connected to both ends of the adjustment rod (11), and a through hole (21) is respectively provided on the front cover (20) and the rear cover (30), and the limit plates (12) are stopped at the outside of the through hole (21), and the adjustment rod (11) is movably passed through the through hole (21) and stopped at the outer periphery of the annular wall (50), and a sealing gasket (40) is provided between the adjustment rod (11) and the hole wall of the through hole (21), and the thickness of the limit plate (12) is B, and Among them, F Z is the friction force between the sealing pad (40) and the adjusting rod (11) when the adjusting rod (11) moves along the through hole (21); L is the distance between the two limiting plates (12); [σ n ] is the allowable compressive stress of the regulating rod (11); S n is the contact area between the limiting plate (12) and the adjusting rod (11); The adjustment mechanism (10) further comprises a knob (13), wherein the knob (13) is provided with a first matching position (131), and the limiting plate (12) is provided with a second matching position (121); wherein one of the first matching position (131) and the second matching position (121) is configured as a groove, and the other is configured as a boss, and the groove is connected to the boss by a snap connection and can limit the relative rotation of the knob (13) and the limiting plate (12).

2. A method for designing a volute of a centrifugal fan for testing, characterized in that: The test centrifugal fan volute design method is used to design the test centrifugal fan volute according to claim 1, and the test centrifugal fan volute design method includes: Get F Z 、F n , L, B, and get Get S n , and obtain the contact stress between the limiting plate (12) and the regulating rod (11) Get [σ n ], according to σ n ≤[σ n ], get L, B, S n With F z Satisfy between:

3. The method for designing a volute of a centrifugal fan for testing according to claim 2, characterized in that: The test centrifugal fan volute design method also includes: Obtain the friction coefficient μ between the adjusting rod (11) and the sealing gasket (40), obtain the extrusion force F between the adjusting rod (11) and the sealing gasket (40), obtain the load safety factor K1 between the adjusting rod (11) and the sealing gasket (40), and obtain F z =μ*K1*F; Among them, 0.3≤μ≤0.5; 3≤K1≤5.

4. The method for designing a volute of a centrifugal fan for testing according to claim 3, characterized in that: The test centrifugal fan volute design method also includes: Obtain the design pressure σ1 between the adjusting rod (11) and the sealing gasket (40), and obtain the contact area S between the adjusting rod (11) and the sealing gasket (40). m , and we get F=σ1*S m , where 4500Pa≤σ1≤7500Pa.

5. The method for designing a volute of a centrifugal fan for testing according to claim 4, characterized in that: The test centrifugal fan volute design method also includes: Obtain the contact length L between the adjusting rod (11) and the sealing gasket (40) along the circumference of the adjusting rod (11) h , obtaining the contact height H between the adjusting rod (11) and the sealing gasket (40) along the axial direction of the adjusting rod (11), and obtaining S m =L h *H.

6. The method for designing a volute of a centrifugal fan for testing according to claim 5, characterized in that: The test centrifugal fan volute design method also includes: Obtain the deformation amount Δ of the sealing gasket (40) squeezed along the radial direction of the adjusting rod (11) M , obtain the diameter d of the adjusting rod (11), and obtain 7. The method for designing a volute of a centrifugal fan for testing according to claim 6, characterized in that: The test centrifugal fan volute design method also includes: Obtain the thickness M of the sealing gasket (40) along the radial direction of the adjusting rod (11), obtain the elastic modulus E of the sealing gasket (40), and obtain Among them, 0.5mm≤M≤5mm.

8. The method for designing a volute of a centrifugal fan for testing according to claim 2, wherein: The test centrifugal fan volute design method also includes: Obtain the contact area correction coefficient K2 between the limiting plate (12) and the regulating rod (11), and obtain S n =K2*π*d*B, where d is the diameter of the adjusting rod (11).

9. The method for designing a volute of a centrifugal fan for testing according to claim 2, wherein: The centrifugal fan volute further comprises a knob (13), the knob (13) being provided with a first matching position (131) extending along its radial direction, and the limiting plate (12) being provided with a second matching position (121) extending along its radial direction; one of the first matching position (131) and the second matching position (121) being configured as a groove, and the other being configured as a boss; the first matching position (131) being capable of engaging with the second matching position (121) and limiting relative rotation between the knob (13) and the limiting plate (12); The test centrifugal fan volute design method also includes: Obtain the radius R of the limiting plate (12), obtain the height V=R*tanα of the second matching position (121) along the axial direction of the limiting plate (12), and the height difference Δ between the thickness of the limiting plate (12) and the second matching position (121) H =BV=BR*tanα; If Δ H >2mm, the second matching position (121) is configured as a groove; If Δ H ≤2mm, then the second matching position (121) is configured as a boss; Wherein, α is the angle between the highest point or the lowest point of the second fitting position (121) and the line connecting the edge of the limiting plate (12) and the surface of the limiting plate (12) along the axial direction of the limiting plate (12), and α≥5°.

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