Centrifugal fan, airflow driving device

Abstract

The application provides a centrifugal fan and an airflow driving device, and belongs to the technical field of air conditioning. The centrifugal fan comprises a centrifugal impeller. The centrifugal impeller is provided with a plurality of blades which are arranged at intervals in the circumferential direction. In the axial projection of the centrifugal impeller, the blade is provided with a pressure surface profile, a suction surface profile, an outlet side profile and an inlet side profile. In the direction from the inlet side profile to the outlet side profile, the thickness of the blade first increases and then decreases. Compared with the equal-thickness blade in the prior art, the thickness of the blade is larger in the middle position and smaller in the inflow and outflow positions of the airflow. The overall strength of the blade can be effectively improved, the problem of weak blade in the prior art can be avoided, and the performance and the operable rotating speed of the fan are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air conditioning, and particularly relates to a centrifugal fan and airflow driving equipment. BACKGROUND

[0002] The centrifugal fan has the characteristics of high pressure coefficient, large flow coefficient and low noise, and is widely used in cooling and ventilation of air conditioning equipment and household electrical equipment. According to the design of the blade shape, it is generally divided into two types of equal-thickness circular arc plate blades and airfoil blades. The equal-thickness circular arc plate blades are easy to process, but there is flow separation in the blade channel, the fan efficiency is low, and the noise is large; the airfoil blades are not easy to process, but compared with the circular arc plate blades, they help to improve the fan efficiency and reduce the fan noise, but the existing airfoil blades are not suitable for the blade design of small-size strong forward multi-wing centrifugal impellers, and the problem of weak blades may occur. SUMMARY

[0003] Therefore, the present application provides a centrifugal fan and airflow driving equipment, which can solve the technical problem that the existing blades are not suitable for the blade design of small-size strong forward multi-wing centrifugal impellers and may cause weak blades in the prior art.

[0004] In order to solve the above problems, the present application provides a centrifugal fan, which comprises a centrifugal impeller, the centrifugal impeller has a plurality of blades arranged at intervals in the circumferential direction, and the blade has a pressure surface profile, a suction surface profile, an outlet side profile and an inlet side profile in the axial projection of the centrifugal impeller. In the direction from the inlet side profile to the outlet side profile, the thickness of the blade first increases and then decreases.

[0005] In some embodiments, the thickness of the blade at any point is y, the junction point of the suction surface profile and the outlet circle of the centrifugal impeller is the first point, the connecting line between the center of the pressure surface profile and the first point is the first line segment, the connecting line between the center of the pressure surface profile and any point of the suction surface profile is the second line segment, the included angle between the first line segment and the second line segment is x, the blade center angle of the blade is γ, the thickness of the blade corresponding to the first point is a,

[0006] y = -3.6218 (x / γ) 5 + 3.329 (x / γ) 4 - 0.8029 (x / γ) 3 + 0.4946 (x / γ) 2 + 0.62 (x / γ)

[0007] 0.0017 + a, wherein 0 ≤ x ≤ γ and 0.8 mm ≤ a ≤ 1.5 mm.

[0008] In some embodiments, the radius of the outlet circle of the centrifugal impeller is m, where 45mm ≤ m ≤ 100mm.

[0009] In some embodiments, the radius of the inlet circle of the centrifugal impeller is n, where 0.87 ≤ n / m ≤ 0.95.

[0010] In some embodiments, the blade inlet angle of the centrifugal impeller is α, where 85°≤α≤95°.

[0011] In some embodiments, the supplementary angle of the centrifugal impeller blade exit angle is β, where 8° ≤ β ≤ 12°.

[0012] In some implementations, γ = 180° - (α + β).

[0013] In some embodiments, the radius of the pressure surface profile is l, l = (m 2 -n 2 ) / [2(m*cosβ-n*cosα)].

[0014] The present invention also provides an airflow driven device, characterized in that it includes the centrifugal fan described above.

[0015] In some embodiments, the airflow driving device includes an air conditioner.

[0016] The present invention provides a centrifugal fan and airflow drive device. Compared with the equal-thickness blades in the prior art, the thickness of the blade is larger in the middle and smaller at the inflow and outflow points of the airflow. This can effectively improve the overall strength of the blade, avoid the problem of weak blades in the prior art, and effectively improve the performance and operating speed of the fan. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a centrifugal fan according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A three-dimensional structural diagram of the centrifugal impeller in the image;

[0019] Figure 3 for Figure 2 A schematic diagram of the blade structure in the image;

[0020] Figure 4 for Figure 2 A schematic diagram showing the relevant dimensions of the blades.

[0021] The reference numerals in the attached figures are as follows:

[0022] 1, centrifugal impeller; 11, blade; 111, pressure surface profile; 112, suction surface profile; 113, outlet side profile; 114, inlet side profile; 21, upper volute; 22, lower volute; 23, air outlet; 31, wheel disc; 32, water beating ring. DETAILED DESCRIPTION

[0023] BRIEF DESCRIPTION OF DRAWINGS Figures 1 to 4 According to an embodiment of the present application, a centrifugal fan is provided, for example a multi-wing centrifugal fan, as shown in Figure 1 The centrifugal fan comprises an upper volute 21 and a lower volute 22, both of which are fastened to form an air duct, in which a centrifugal impeller 1 is arranged, which is preferably a small-size strong forward multi-wing centrifugal fan blade, as shown in Figure 2 The centrifugal impeller 1 has a plurality of blades 11 arranged at intervals in the circumferential direction, as shown in Figure 3 In the axial projection of the centrifugal impeller 1, the blade 11 has a pressure surface profile 111, a suction surface profile 112, an outlet side profile 113 and an inlet side profile 114, and in the direction from the inlet side profile 114 to the outlet side profile 113, the thickness of the blade 11 first increases and then decreases. In this technical solution, compared with the equal-thickness blade in the prior art, the thickness of the blade 11 is larger in the middle position and smaller at the inflow and outflow positions of the airflow, which can effectively improve the overall strength of the blade 11, avoid the problem of weak blades in the prior art, and effectively improve the performance and operating speed of the fan.

[0024] In a preferred embodiment, as shown in Figure 4 The thickness of the blade 11 at any point is y, the junction of the suction surface profile 112 and the outlet circle of the centrifugal impeller 1 is the first point, the line segment between the center of the pressure surface profile 111 and the first point is the first line segment, the line segment between the center of the pressure surface profile 111 and any point of the suction surface profile 112 is the second line segment, the included angle between the first line segment and the second line segment is x, the blade center angle of the blade 11 is γ, the thickness of the blade 11 corresponding to the first point is a,

[0025] y = -3.6218(x / γ) 5 + 3.329(x / γ) 4 - 0.8029(x / γ) 3 + 0.4946(x / γ) 2 + 0.62(x / γ)

[0026] 0.0017+a, wherein 0≤x≤γ and 0.8mm≤a≤1.5mm, in the technical solution, different from the structure of the traditional equal-thickness circular-arc plate and the airfoil blade, the pressure surface and the suction surface are coupled and designed, and the blade thickness is optimized, so that the centrifugal impeller 1 can be especially applied to a small-size strong forward multi-wing centrifugal fan blade, the problem of weak blades in the small-size strong forward multi-wing centrifugal fan blade during the blade type design is effectively solved, and the performance and the operating speed of the fan are effectively improved. It should be noted that in the aforementioned pressure surface and suction surface double-surface coupling function, a only needs to be brought into the function for operation when the value corresponding to the dimension mm is obtained, and the dimension of the final y value is also defined as mm, and other calculation factors are not dimensioned.

[0027] Further referring to Figure 4 As shown in the figure, the radius of the outlet circle of the centrifugal impeller 1 is m, 45mm≤m≤100mm, the radius of the inlet circle of the centrifugal impeller 1 is n, 0.87≤n / m≤0.95; the blade inlet angle of the centrifugal impeller 1 is α, 85°≤α≤95°; the supplementary angle of the blade outlet angle of the centrifugal impeller 1 is β, 8°≤β≤12°; γ=180°-(α+β); the radius of the pressure surface profile 111 is l, l=(m 2 -n 2 ) / [2(m*cosβ-n*cosα)]. Further optimization of the foregoing parameters can further solve the problem of weak blades in the small-size strong forward multi-wing centrifugal fan blade during the blade type design.

[0028] Referring to Figure 2 As shown in the figure, in a specific embodiment, the centrifugal fan is a double-inlet centrifugal fan, that is, it has two groups of blades 11 sharing one wheel disc 31, and the water striking ring 32 is connected to one end of the principle wheel disc 31 of each group of blades 11, so that the structure of each group of blades 11 is reliable and stable.

[0029] In a specific embodiment, the strong forward multi-wing centrifugal fan blade applies the small-size strong forward multi-wing centrifugal fan blade type design method of the pressure surface and the suction surface double-surface coupling function design of the application, and compared with the conventional blade type design, the fan air volume is increased by more than 15% under the same impeller size, and the actual measurement data are shown in Table 1.

[0030] Table 1 Comparison of actual measurement air volume of different blade type design methods

[0031]

[0032]

[0033] According to the embodiment of the application, a gas flow driving device is also provided, characterized in that it comprises the centrifugal fan described above, and the gas flow driving device comprises an air conditioner.

[0034] Those skilled in the art can understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0035] The above is only the preferred embodiment of the present application, and should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, can also make a number of improvements and variations, these improvements and variations should be considered as the protection scope of the present application.

Claims

1. A centrifugal fan comprising a centrifugal impeller (1) having a plurality of blades (11) arranged at intervals in a circumferential direction, characterized by, In the axial projection of the centrifugal impeller (1), the blade (11) has a pressure surface profile (111), a suction surface profile (112), an outlet side profile (113) and an inlet side profile (114), in the direction from the inlet side profile (114) to the outlet side profile (113), the thickness of the blade (11) first increases and then decreases; the thickness of the blade (11) at any point is y, the junction point of the suction surface profile (112) and the outlet circle of the centrifugal impeller (1) is a first point, the connecting line between the center of the pressure surface profile (111) and the first point is a first line segment, the connecting line between the center of the pressure surface profile (111) and any point of the suction surface profile (112) is a second line segment, the included angle between the first line segment and the second line segment is x, the blade center angle of the blade (11) is γ, the thickness of the blade (11) corresponding to the first point is a, y = -3.6218(x / γ) 5 +3.329(x / γ) 4 -0.8029(x / γ) 3 +0.4946(x / γ) 2 +0.62(x / γ)-0.0017+a, wherein 0≤x≤γ and 0.8mm≤a≤1.5mm.

2. The centrifugal fan of claim 1, wherein The radius of the outlet circle of the centrifugal impeller (1) is m, 45mm≤m≤100mm.

3. The centrifugal fan of claim 2, wherein The radius of the inlet circle of the centrifugal impeller (1) is n, 0.87≤n / m≤0.

95.

4. The centrifugal fan of claim 3, wherein The blade inlet angle of the centrifugal impeller (1) is α, 85°≤α≤95°.

5. The centrifugal fan of claim 4, wherein The supplementary angle of the blade outlet angle of the centrifugal impeller (1) is β, 8°≤β≤12°.

6. The centrifugal fan of claim 5, wherein γ=180°-(α+β).

7. The centrifugal fan of claim 6, wherein The radius of the pressure surface profile (111) is l, l = (m 2 -n 2 ) / [2(m*cosβ-n*cosα)].

8. An airflow driving apparatus, characterized by comprising: The centrifugal fan comprises the centrifugal fan according to any one of claims 1 to 7.

9. The airflow driving apparatus according to claim 8, wherein The airflow driving device comprises an air conditioner.

Images