Cross-flow fan blade and air conditioner

Abstract

The embodiment of the application provides a cross-flow fan blade and an air conditioner, and relates to the technical field of air conditioners. The blade of the cross-flow fan blade provided by the embodiment of the application is arranged in an inclined manner, and the spacing between the blades is uneven, so that the cross-flow fan blade has different airflow flow states in the axial direction, resonance is avoided during operation, and thus the noise of the cross-flow fan blade during operation is reduced. The air conditioner provided by the embodiment of the application comprises the cross-flow fan blade, and thus has corresponding beneficial effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a cross-flow fan blade and an air conditioner. BACKGROUND

[0002] The cross-flow fan blade is an important component of an indoor unit of an air conditioner, and the aerodynamic performance of the cross-flow fan blade directly affects the air volume and noise value of the indoor unit in operation. The geometric shape parameters of the blade of the cross-flow fan blade, the blade distribution and the installation angle all have an important influence on the ventilation characteristics of the fan. Since the existing cross-flow fan blade structure is not reasonable enough, there is a problem of relatively large noise in operation. SUMMARY

[0003] The problem solved by the present application is the problem of relatively large noise in operation of the existing cross-flow fan blade.

[0004] To solve the above problems, in a first aspect, the present application provides a cross-flow fan blade, comprising two end plates and a plurality of blades arranged between the two end plates, the extension direction of the blades is inclined relative to the axis of the cross-flow fan blade, and the plurality of blades are arranged at intervals in the circumferential direction of the axis of the cross-flow fan blade and the interval distances are non-uniform.

[0005] In the embodiments of the present application, the blades are arranged in an inclined manner, and the intervals between the blades are non-uniform, so that the cross-flow fan blade has different airflow flow patterns in the axial direction, resonance is avoided in operation, and the noise of the cross-flow fan blade in operation is reduced.

[0006] In an optional implementation, the cross-flow fan blade comprises N blades arranged in the circumferential direction of the axis, the 1st, 2nd, …, i-th, …, Nth blades are arranged at intervals in the preset rotation direction around the axis of the cross-flow fan blade, the 1st blade is taken as a reference blade, and the relative central angle of the i-th blade around the axis in the preset rotation direction relative to the reference blade is θ i , and the relative central angle of each blade satisfies:

[0007]

[0008] In the present embodiment, under the condition of satisfying the above relationship, the entire blade has a better dynamic balance, which can ensure that the radial centrifugal forces are balanced at the same time, and the aerodynamic noise caused by unbalanced centrifugal force is avoided.

[0009] In an optional implementation, each blade has a corresponding interval angle, the interval angle β i of the i-th blade is θ i - θ i-1 , and the interval angle β1 of the 1st blade is 2π- θ NThe angle range of the interval angle is [360 / N-s, 360 / N+s], wherein s is taken from [0.5, 3]. In the embodiment, although the interval angles are not completely same, which is beneficial to reduce the rotating noise, if the angle range of the interval angle is too large, the aerodynamic performance will be poor, thus the angle of the interval angle is limited in a certain range.

[0010] In the optional embodiment, the variance of the angle of the interval angle of each blade is not more than 1.5. In the embodiment, the variance of the angle of the interval angle is controlled in a certain range, which is beneficial to ensure the aerodynamic performance of the cross-flow fan blade.

[0011] In the optional embodiment, the blade has a proximal side close to the axis and a distal side far from the axis in the width direction of the blade itself, the distance between the distal side of the blade and the axis is R1, the distance between the proximal side of the blade and the axis is R2, the radial ratio m of the blade is R2 / R1, and the value range of m is [0.75, 0.8]. When R1 is constant, if the value of m is too small, the central flow area of the cross-flow fan blade and the area between the primary air inlet and the secondary air outlet of the cross-flow fan blade are reduced; if the value of m is too large, the blade is not beneficial to work. Both of the above cases are easy to cause low air outlet efficiency, thus controlling the radial ratio m in a reasonable range can ensure the good aerodynamic performance of the cross-flow fan blade.

[0012] In the optional embodiment, the cross section of the blade perpendicular to the axis is a characteristic cross section of the blade, the characteristic cross section of the blade has a distal end corresponding to the distal side of the blade and a proximal end corresponding to the proximal side of the blade, the characteristic cross section of the blade is arc-shaped, the tangent line of the median arc of the characteristic cross section at the distal end is a first tangent line, the tangent line of the median arc of the characteristic cross section at the proximal end is a second tangent line, the perpendicular line of the line connecting the distal end of the characteristic cross section and the axis is a first perpendicular line, the perpendicular line of the line connecting the proximal end of the characteristic cross section and the axis is a second perpendicular line, the included angle y1 between the first perpendicular line and the first tangent line is taken from the range of [17°, 26°], and the included angle y2 between the second perpendicular line and the second tangent line is taken from the range of [80°, 100°]. According to the direction of the airflow flowing into the cross-flow fan blade from outside to inside, the included angle y1 and the included angle y2 are the inlet angle and the outlet angle respectively, and by reasonably taking the inlet angle and the outlet angle, the cross-flow fan blade can have better aerodynamic performance and improve the air outlet efficiency.

[0013] In the optional embodiment, the camber angle of the blade is taken from the range of [70°, 80°], the camber angle of the blade is the included angle between the perpendicular line of the first tangent line at the distal end of the characteristic cross section and the perpendicular line of the first tangent line at the proximal end of the characteristic cross section, and the opening direction of the camber angle is towards the characteristic cross section. If the camber angle of the blade is too large, the airflow separation on the suction surface of the airfoil is more obvious, the turbulence is intensified, the energy loss is increased, and even noise is caused; if the camber angle of the blade is too small, the work capacity of the blade is reduced. Therefore, the camber angle of the blade is limited in [70°, 80°] in the embodiment, so as to ensure the good air outlet capacity of the blade.

[0014] In an optional embodiment, the unit twist angle A of the blade is the angle of deflection of the blade per millimeter in the axial direction, and the unit twist angle A of the blade ranges from (0, k], where k = 1 / (a*t 2 +b*t+c*sin(t)-d), t = ω*π / 180, ω is the bending angle of the blade, a ranges from [11, 14], b ranges from [2.5-3.5], c ranges from [0.08, 0.12], and d ranges from [16, 19].

[0015] In an optional embodiment, the unit twist angle A of the blade is the angle of deflection of the blade per millimeter in the axial direction, and the unit twist angle A of the blade ranges from [0.043, 0.1]. The unit twist angle β of the inclined blade has a great influence on the noise and air volume of the fan blade. When the unit twist angle β increases, the noise value decreases and the air volume decreases. When β is too large, the air volume decreases significantly. When β is too small, the noise improvement is not obvious. Therefore, the range of the unit twist angle is limited in this embodiment, which can take into account the output air volume and improve the noise.

[0016] In a second aspect, the application provides an air conditioner comprising the cross-flow fan blade of any one of the preceding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a schematic view of a cross-flow fan blade according to an embodiment of the application;

[0018] Figure 2 FIG. 2 is a sectional view of the cross-flow fan blade according to an embodiment of the application;

[0019] Figure 3 FIG. 3 is a first schematic view of a representative cross-section of the fan blade according to an embodiment of the application;

[0020] Figure 4 FIG. 4 is a second schematic view of a representative cross-section of the fan blade according to an embodiment of the application.

[0021] FIG. 1 is a schematic view of a cross-flow fan blade according to an embodiment of the application; DETAILED DESCRIPTION

[0022] Cross-flow fan blades are a crucial component of air conditioning indoor units, typically driven by a motor to circulate indoor air. The aerodynamic performance of the cross-flow fan blades directly affects the airflow and noise level of the indoor unit. The geometric parameters of the cross-flow fan blades, their distribution, and the installation angle all significantly influence their ventilation characteristics. Due to imperfections in existing cross-flow fan structures—for example, blades extending in the same direction as the axial axis or having uniform blade spacing—the airflow patterns become similar along the axial direction of the cross-flow fan, easily leading to resonance or in-line resonance. This results in significant noise levels during operation.

[0023] To address the issue of excessive noise in existing cross-flow fan blades, this application provides a novel cross-flow fan blade. By improving the shape and arrangement of the blade, noise is reduced while maintaining airflow.

[0024] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of a cross-flow fan blade 100 in one embodiment of this application. Figure 1 As shown, the cross-flow fan blade 100 includes two end plates 110 and multiple blades 120, with the multiple blades 120 disposed between the two end plates 110. In this embodiment, the extension direction of the blades 120 is inclined relative to the axis of the cross-flow fan blade, and the multiple blades 120 are arranged at intervals along the circumference of the axis of the cross-flow fan blade 100 with non-uniform spacing. This arrangement can disrupt the airflow pattern at various positions of the cross-flow fan blade 100, reduce the resonance of the blades 120, and reduce noise. Specifically, in this embodiment, the cross-flow fan blade 100 has multiple sections in the axial direction, each section being separated by a partition 130, and each blade 120 in each section is arranged around the axis. In this embodiment, the adjacent ends of the blades 120 in adjacent sections are in a one-to-one correspondence; in other words, in the axial direction of the cross-flow fan blade 100, the head end of the blade 120 of the subsequent section is axially opposite to the tail end of the blade 120 of the previous section without misalignment.

[0026] In an optional embodiment, the blades 120 of each section are arranged in the same way, so that the cross-sectional distribution of the blades 120 at all positions in the axial direction of the entire cross-flow fan 100 (except for the end plate 110 and the partition plate 130) is the same. Of course, in other optional embodiments, the cross-flow fan 100 may also have only one section without partition plate 130.

[0027] Figure 2 This is a cross-sectional view of a cross-flow fan blade 100 in one embodiment of this application. The cutting direction is perpendicular to the axis of the cross-flow fan blade 100. Figure 2As shown, taking any one section as an example, the number of the blades 120 around the axis is N, the 1st, 2nd, …, i-th, …, N-th blades are arranged in sequence around the axis of the cross-flow fan blade 100 in a preset rotation direction, taking the 1st blade as a reference blade, the relative central angle of the i-th blade around the axis relative to the reference blade in the preset rotation direction is θ i , the relative central angle of each blade satisfies:

[0028]

[0029] In the embodiment, although the blades 120 are not uniformly distributed in the local circumferential direction, the sum of the cosine function and the sine function of the relative central angle of the blades 120 is zero, which means that the overall distribution can meet the balance requirement. In the case of satisfying the above relationship, the entire cross-flow fan blade 100 has better dynamic balance, which can ensure that the radial centrifugal force is balanced at the same time, and avoid the increase of aerodynamic noise caused by unbalanced centrifugal force.

[0030] In the embodiment, each blade 120 has a corresponding interval angle, the interval angle β i of the i-th blade is θ i - θ i-1 , the interval angle β1 of the 1st blade is 2π- θ N , the angle range of the interval angle is [360 / N- σ, 360 / N+ σ], and σ is taken as [0.5, 3]. In the embodiment, although the interval angles are not completely the same, which is beneficial to reduce the rotation noise, but if the angle range of the interval angle is too large, it will lead to poor aerodynamic performance, therefore, the angle of the interval angle is limited within a certain range.

[0031] Further, the variance of the angle of the interval angle of each blade 120 is not greater than 1.5. In the embodiment, the variance of the angle of the interval angle is controlled within a certain range, which is beneficial to ensure the aerodynamic performance of the cross-flow fan blade 100. In the embodiment, the unit of the variance is square of angle (°).

[0032] Figure 3 is a first schematic view of a representative section 121 of the blade 120 in an embodiment of the present application. As shown, the section of the blade 120 perpendicular to the axis is the representative section 121 of the blade 120, the representative section 121 of the blade 120 has a distal end 122 corresponding to the distal side of the blade 120 and a proximal end 123 corresponding to the proximal side of the blade 120, and the representative section 121 of the blade 120 is arc-shaped. Figure 3

[0033] ​In this embodiment, the blade 120 has a proximal side relatively close to the axis and a distal side relatively far from the axis in its own width direction. The distal side of the blade 120 corresponds to the distal end 122 of its intrinsic cross-section, and the proximal side corresponds to the proximal end 123 of its intrinsic cross-section. The distance between the distal side of the blade 120 and the axis is R1, and the distance between the proximal side of the blade 120 and the axis is R2. The radial ratio m of the blade 120 is R2 / R1, and the value of m ranges from [0.75, 0.8]. When R1 is constant, if the value of m is too small, the central flow area of ​​the cross-flow fan 100 decreases, and the area between the primary air intake and secondary air outlet of the cross-flow fan 100 decreases; if the value of m is too large, it is not conducive to the work done by the blade 120. Both of these situations can easily lead to low air outlet efficiency. Therefore, controlling the radial ratio m within a reasonable range can ensure good aerodynamic performance of the cross-flow fan 100.

[0034] In an optional embodiment, the tangent of the mid-arc line characterizing section 121 at the distal end 122 is the first tangent. Figure 3 In section L1), the tangent to the mid-arc line of section 121 near end 123 is the second tangent. Figure 3 The perpendicular line from the line connecting the distal end 122 to the axis is the first perpendicular line (L2). Figure 3 The perpendicular line from the line connecting the proximal end 123 to the axis is the second perpendicular line (L3). Figure 3 In section L4), the angle γ1 between the first perpendicular line and the first tangent ranges from [17°, 26°], and the angle γ2 between the second perpendicular line and the second tangent ranges from [80°, 100°]. Following the direction of airflow into the cross-flow fan 100 from the outside in, angles γ1 and γ2 are the inlet angle and outlet angle, respectively. By appropriately selecting the values ​​of the inlet and outlet angles, the cross-flow fan 100 can be guaranteed to have better aerodynamic performance and improve airflow efficiency.

[0035] Figure 4 This is a second schematic diagram of the characterizing section 121 of the blade 120 in one embodiment of this application. In an optional embodiment, the camber angle of the blade 120 ranges from [70°, 80°], and the camber angle ω of the blade 120 is the perpendicular line from the first tangent in the characterizing section 121 of the blade 120 to the distal end 122 of the characterizing section 121. Figure 4 The perpendicular line between L5 and the first tangent at the proximal end 123 of the characterizing section 121 ( Figure 4The opening direction of the camber angle is towards the characteristic section 121. If the camber angle of the blade 120 is too large, the air flow separation on the suction surface of the airfoil is more obvious, which intensifies the turbulence, increases the energy loss, and even causes noise; if the camber angle is too small, the blade 120 has a poor air output capacity. Therefore, the camber angle of the blade 120 is limited to [70°, 80°] in the embodiment, so as to ensure that the blade 120 has a good air output capacity. It should be understood that if the characteristic section of the blade 120 is a uniform circular arc, that is, the curvature is the same at each position, then the intersection of the perpendicular line of the first tangent at the far end 122 of the characteristic section 121 and the perpendicular line of the first tangent at the near end 123 of the characteristic section 121 is the center of the circular arc corresponding to the camber line of the characteristic section, and the camber angle of the blade 120 is equal to the central angle of the camber line of the characteristic section.

[0036] In Figure 4 the characteristic section, the chord corresponding to the camber line of the characteristic section is L. The first installation angle ζ1 and the second installation angle ζ2 of the blade 120 are the angles between the chord and the radii of the far end 122 and the near end 123 of the characteristic section, respectively. The radius of the far end 122 is the line R1 connecting the far end 122 of the characteristic section and the axis (a point in the figure), and the radius of the near end 123 is the line R2 connecting the near end 123 of the characteristic section and the axis. Each parameter satisfies the following relationship:

[0037]

[0038]

[0039] Therefore, the chord length L and the installation angle ζ2 are determined when the ζ1 is determined, and vice versa. Optionally, the range of ζ1 is [25°, 30°], and the range of ζ2 is [35°, 40°].

[0040] In an optional embodiment, the unit twist angle A of the blade 120 is the angle of the blade 120 deflected in the direction of the axis per millimeter of extension, and the unit twist angle A of the blade 120 is in the range of (0, k], where k = 1 / (a*t 2 +b*t+c*sin(t)-d), t = ω*π / 180, a is in the range of [11, 14], b is in the range of [2.5-3.5], c is in the range of [0.08, 0.12], and d is in the range of [16, 19]. In a specific embodiment, a is 12.5814, b is 3, c is 0.1, and d is 17.4041.

[0041] In an optional embodiment, the range of the unit twist angle A of the blade 120 is set to [0.043, 0.1]. The unit twist angle of the inclined blade 120 has a great influence on the noise and the air volume of the fan blade. When the unit twist angle A increases, the noise value decreases and the air volume decreases. When A is too large, the air volume decreases significantly. When A is too small, the noise improvement is not obvious. Therefore, the range of the unit twist angle is limited in the embodiment, which can take into account the output air volume and improve the noise.

[0042] The above describes the parameter determination method of the blade 120 of the cross-flow fan blade 100. In a specific embodiment, the parameters of the cross-flow fan blade 100 are as follows:

[0043] R1 R2 γ1 γ2 ζ1 ζ2 L ω A 51.81 40.24 22 88 29.5 39.35 13.98 75.85 0.08697

[0044] The following table compares the cross-flow fan blade 100 of the present embodiment with the cross-flow fan blade of the prior art with uniform non-inclined blades in actual application.

[0045]

[0046] At the same speed, the noise of the cross-flow fan blade 100 provided in the embodiment is reduced, and the air volume is slightly reduced. As shown in the above table, at the same air volume, the noise is reduced by 0.5-2dB. The rotating noise of the fan blade is significantly reduced, and the higher the speed, the more obvious the noise advantage.

[0047] In addition, the embodiment of the present application also provides an air conditioner (not shown in the figure) comprising the cross-flow fan blade provided in the above embodiment. The air conditioner can be an air conditioner indoor unit, and specifically can be a wall-mounted air conditioner indoor unit.

[0048] In summary, in the embodiment of the present application, the blade 120 is arranged to be inclined, and the spacing between the blades 120 is non-uniform, so that the cross-flow fan blade 100 has different airflow flow patterns in the axial direction, avoiding resonance during operation, thereby reducing the noise of the cross-flow fan blade 100 during operation. The air conditioner provided in the embodiment of the present application comprises the above cross-flow fan blade 100, and therefore also has the corresponding beneficial effects.

[0049] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the range defined by the claims.

Claims

1. A cross-flow fan blade, characterized in that, It includes two end plates (110) and a plurality of blades (120) disposed between the two end plates (110). The extension direction of the blades (120) is inclined relative to the axis of the cross-flow fan (100). The plurality of blades (120) are arranged at intervals in the circumferential direction of the axis of the cross-flow fan (100) and the intervals are non-uniform. The cross-flow fan blade (100) includes N blades (120) arranged circumferentially along the axis. The first, second, ..., i, N blades (120) are arranged at intervals around the axis of the cross-flow fan blade (100) in a preset rotation direction. Taking the first blade (120) as the reference blade, the central angle between the i-th blade (120) and the reference blade in the preset rotation direction around the axis is θ. i Each of the blades (120) has a corresponding spacing angle, and the spacing angle β of the i-th blade (120) is... i For θ i -θ i-1 The spacing angle β1 of the first blade (120) is 2π-θ N The angle range of the interval angle is [360 / N-σ, 360 / N+σ], where σ takes the values ​​[0.5, 3]. The blade (120) has a proximal side relatively close to the axis and a distal side relatively far from the axis in its own width direction. The distance between the distal side of the blade (120) and the axis is R1, and the distance between the proximal side of the blade (120) and the axis is R2. The radial ratio of the blade (120) is m = R2 / R1, and the value of m is in the range of [0.75, 0.8].

2. The cross-flow fan blade according to claim 1, characterized in that, The relative central angles of each of the blades (120) satisfy: , 。 3. The cross-flow fan blade according to claim 1, characterized in that, The variance of the angle of the interval angle of each of the blades (120) is not greater than 1.

5.

4. The cross-flow fan blade according to claim 1, characterized in that, The section of the blade (120) perpendicular to the axis is the characterizing section (121) of the blade (120). The characterizing section (121) of the blade (120) has a distal end (122) corresponding to the distal side of the blade (120) and a proximal end (123) corresponding to the proximal side of the blade (120). The characterizing section (121) of the blade (120) is arc-shaped, and the middle arc line of the characterizing section (121) is cut at the distal end (122). The line is the first tangent, the tangent of the middle arc of the characterizing section (121) at the proximal end (123) is the second tangent, the perpendicular line of the line connecting the distal end (122) and the axis is the first perpendicular line, the perpendicular line of the line connecting the proximal end (123) and the axis is the second perpendicular line, the angle γ1 between the first perpendicular line and the first tangent ranges from [17°, 26°], and the angle γ2 between the second perpendicular line and the second tangent ranges from [80°, 100°].

5. The cross-flow fan blade according to claim 4, characterized in that, The camber angle of the blade (120) is in the range of [70°, 80°]. The camber angle of the blade (120) is the angle between the perpendicular line of the first tangent at the far end (122) of the characterizing section (121) and the perpendicular line of the first tangent at the near end (123) of the characterizing section (121), and the opening direction of the camber angle is towards the characterizing section (121).

6. The cross-flow fan blade according to claim 5, characterized in that, The unit twist angle A of the blade (120) is the angle by which the blade (120) deflects for every millimeter it extends along the axial direction. The value range of the unit twist angle A of the blade (120) is (0, k], where k = 1 / (a*t) 2 +b*t+c*sin(t)-d), t=ω*π / 180, ω is the curvature angle of the blade (120), a ranges from [11, 14], b ranges from [2.5~3.5], c ranges from [0.08, 0.12], and d ranges from [16, 19].

7. The cross-flow fan blade according to claim 1, characterized in that, The unit twist angle A of the blade (120) is the angle by which the blade (120) deflects for every millimeter it extends along the axial direction, and the value range of the unit twist angle A of the blade (120) is [0.043, 0.1].

8. An air conditioner, characterized in that, Includes the cross-flow fan blades according to any one of claims 1-7.

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