Cross-flow fan blade, air conditioner and control method of air conditioner

Abstract

The invention provides a cross-flow fan blade, an air conditioner and a control method thereof.The cross-flow fan blade comprises a plurality of middle-section fan blades, and each middle-section fan blade comprises a fan blade base disc and a plurality of blades arranged around the central axis of the middle-section fan blade at intervals; each blade is provided with a blade front edge, a blade rear edge and a blade wing body connected between the blade front edge and the blade rear edge, the blade front edge is provided with front edge vortex breaking teeth arranged in the length direction of the blade at intervals, and the blade rear edge is provided with rear edge flow guide teeth arranged in the length direction of the blade at intervals. Large-scale vortexes are effectively decomposed, pressure fluctuation of the turbulence boundary is improved, meanwhile, excessive disturbance of main flow is avoided, and therefore pneumatic noise of the cross-flow fan blade is reduced, meanwhile, the trailing edge flow guide teeth can further disperse vortexes gathered at the tail ends of the blade wings due to airflow scouring, and vortex noise is restrained.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning, and in particular relates to a cross-flow fan blade, an air conditioner and a control method thereof. Background Art

[0002] The conflict between modern air conditioning systems' energy efficiency and noise generation remains a persistent pain point for users. Air conditioning noise is essentially driven by two types of turbulence: discrete noise generated by the high-speed shearing between fan blades and air; and eddy currents generated by airflow passing through narrow components, such as fan blades. This turbulent air is then transferred to the air deflector at the air outlet, exacerbating the vibration noise.

[0003] To address the problem of fan blade noise, existing technologies mainly rely on the following two solutions: one is passive sound insulation, which absorbs noise by thickening sound insulation cotton or adding damping materials. However, this method significantly increases the equipment volume and air duct resistance, resulting in reduced energy efficiency; the other is air duct optimization, which uses streamlined air ducts to reduce airflow separation, but its design cannot specifically suppress broadband noise caused by turbulence.

[0004] The noise reduction solutions for wind guides or air outlets mainly include active noise reduction and passive noise reduction. For example, in the related technology, a sound absorption module and an active noise reduction module are set in the airflow output channel of the wind sweeping blade assembly, and the noise is reduced by combining physical sound absorption and anti-phase sound wave cancellation technology. However, it is only effective when the noise conditions meet a specific threshold, and it is not possible to generalize the suppression of noise of different frequencies at different wind speeds; alternatively, a damping block or an external silencer is set near the air outlet to reduce eddy currents and improve noise, but this will increase the size of the equipment and the noise reduction effect is limited. Summary of the Invention

[0005] Therefore, the present invention provides a cross-flow fan blade, an air conditioner and a control method thereof, which can overcome the technical problem in the related art that the fan blade cuts the airflow during rotation to generate discrete noise and eddy current crushing noise, affecting the user's home environment usage experience.

[0006] In order to solve the above problems, the present invention provides a cross-flow fan blade, including a multi-section middle-section fan blade, the middle-section fan blade including a fan base and a plurality of blades arranged at intervals around the central axis of the middle-section fan blade, each of the blades having a blade leading edge, a blade trailing edge and a blade wing body connected between the blade leading edge and the blade trailing edge, the blade leading edge is provided with a leading edge vortex-breaking tooth arranged at intervals along the length direction of the blade, and the blade trailing edge is provided with a trailing edge guide tooth arranged at intervals along the length direction of the blade.

[0007] In some embodiments, the leading edge vortex-breaking teeth include a plurality of large teeth spaced apart along the length direction of the blade and a plurality of small teeth between the large teeth, the tooth height of each large tooth being greater than the tooth height of each small tooth, and the tooth thickness of each large tooth being greater than the tooth thickness of each small tooth.

[0008] In some embodiments, the tooth height of each large tooth is 0.8±0.08 mm and the tooth width is 0.7±0.07 mm; the tooth height of each small tooth is 0.7±0.07 mm and the tooth width is 0.15±0.015 mm; and / or, the number of small teeth arranged between two adjacent large teeth is four.

[0009] In some embodiments, the distance between two adjacent large teeth is equal, and the distance between two adjacent small teeth is equal; and / or, the distance between two adjacent large teeth is 1.6±0.16 mm.

[0010] In some embodiments, the top end surface of each large tooth and each small tooth has a rounded transition; and / or, the front and rear walls of each large tooth and each small tooth extend along the corresponding contour lines of the front and rear walls of the blade body, and the front and rear walls of each large tooth and the front and rear walls of each small tooth intersect at the tooth top.

[0011] In some embodiments, the tooth height of each guide tooth is 3.4±0.34 mm, the tooth width is 0.5±0.05 mm, and the tooth pitch is 0.5±0.05 mm; and / or, the front wall surface of each guide tooth extends in correspondence with the contour line of the front wall surface of the blade body, and the tooth root thickness of the guide tooth is 60% of the trailing edge thickness of the blade body.

[0012] In some embodiments, the rear wall surface of the tooth root of each guide tooth is connected to the rear wall surface of the blade body by an arc transition.

[0013] The present invention further provides an air conditioner, comprising a cross-flow fan, wherein the cross-flow fan comprises cross-flow blades, and the cross-flow blades are the cross-flow blades described above.

[0014] In some embodiments, the air conditioner further includes an air deflector assembly at the air outlet of the air conditioner, wherein the air deflector assembly includes an air deflector, an acceleration detection device, and a piezoelectric actuator array, wherein the acceleration detection device is used to detect the real-time acceleration information of the air deflector during operation and extract its vibration spectrum, and the piezoelectric actuator array is used to control the air deflector to produce reverse deformation.

[0015] In some embodiments, the acceleration detection device is disposed at the rotation axis of the wind deflector, and the piezoelectric actuator array is disposed on the leeward side of the wind deflector; and / or the acceleration detection device is a three-axis acceleration sensor.

[0016] The present invention also provides a method for controlling the air conditioner, comprising the following steps:

[0017] Obtaining a target frequency f1 based on the real-time rotation speed of the crossflow blade and obtaining a main frequency f2 of the vibration spectrum of the air guide plate based on the acceleration detection device;

[0018] Determine whether f2≈kf1 or f2≈kf0 holds true, where f0 is the natural frequency of the air deflector and k=1, 2, 3, ...; when f2≈kf1 or f2≈kf0 holds true, control the piezoelectric actuator array to generate a reverse phase to apply a reverse displacement to the air deflector, until f2≈kf1 or f2≈kf0 does not hold true, then control the piezoelectric actuator array to stop operating.

[0019] The crossflow fan blade, air conditioner and control method thereof provided by the present invention have the following beneficial effects:

[0020] A plurality of leading edge vortex-breaking teeth are arranged on the leading edge of each blade, which can effectively decompose large-scale vortices (that is, the incoming air flow is subdivided and cut, and large vortices are decomposed into micro-vortices), improve the pressure fluctuation at the turbulent boundary (that is, improve the turbulence in the air duct), and avoid excessive disturbance of the mainstream, thereby reducing the aerodynamic noise of the crossflow blade. At the same time, a plurality of trailing edge guide teeth are arranged on the trailing edge of each blade, which can further disperse the vortex gathered by the airflow scouring at the blade tip (that is, the trailing edge of the blade), thereby suppressing the vortex noise and improving the user's comfort. Through simulation analysis and comparison with the existing The technical solution (without leading edge vortex breaking teeth and trailing edge guide teeth) and the technical solution of the present invention (with leading edge vortex breaking teeth and trailing edge guide teeth) were compared. It was found that when the steady state was reached under the same fan speed and airflow conditions, the static pressure intensity of the two shedding vortex centers at point A in the air duct flow field of the technical solution of the present invention was reduced from 46Pa to 34Pa, a reduction of about 26%, and the airflow distribution was more uniform, thereby reducing the aerodynamic noise in the air duct; the position of the eccentric vortex center at point B was offset by about 5% toward the central axis of the fan blade, reducing the turbulence and disturbance excited when the airflow passed through the tip of the fan blade, thereby reducing the aerodynamic noise generated by the fan blade;

[0021] The leading edge vortex-breaking teeth are composed of multiple large and small teeth. The large teeth can effectively suppress low-frequency noise (such as low-frequency noise generated by blade vibration) while reducing large-scale vortices in the airflow. The small teeth can effectively suppress high-frequency noise (such as high-frequency noise generated by airflow impact and turbulence) and absorb high-frequency sound waves. The mixed use of large and small teeth can provide more comprehensive noise reduction frequency coverage and effectively reduce noise across the entire spectrum. In addition, the mixed design of large and small teeth can also optimize the smoothness of the airflow, reduce airflow separation, and further reduce noise.

[0022] The proportional relationship between the root thickness of the guide teeth and the thickness of the trailing edge of the blade body is defined, and the connection between the two is processed with an arc transition. This can accelerate the airflow from the end of the rear wall of the blade body to the trailing edge guide teeth, preventing the airflow from adhering and gathering to form secondary vortices.

[0023] A piezoelectric actuator array is set on the wall of the air guide plate, which can convert the input voltage signal into material deformation, thereby applying displacement to the air guide plate. The acceleration detection device can extract the vibration spectrum of the air guide plate at the current speed of the cross-flow fan based on the acceleration information of the air guide plate during operation, extract the main frequency through the vibration analysis module, and then convert the spectrum signal into a voltage signal and transmit it to the piezoelectric actuator array to drive the air guide plate to perform reverse vibration displacement, thereby solving the aerodynamic coupling and mechanical coupling control problems of the air guide plate vibration noise and the cross-flow fan speed. Combined with vibration characteristic analysis and active noise reduction technology, it is suitable for noise suppression of the air guide plate under different speed conditions of the air conditioner. It can use electromechanical joint control means to calculate and analyze the vibration characteristics at different speeds to ensure the reliability and adaptability of the noise reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. The drawings described below are merely exemplary. Those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0025] Figure 1 Schematic diagram of the structure of the air conditioner in the embodiment of the present invention (excluding components such as the housing);

[0026] Figure 2 yes Figure 1 Schematic diagram of the three-dimensional structure of the cross-flow fan;

[0027] Figure 3 yes Figure 2 Schematic diagram of the three-dimensional structure of the middle section wind blade;

[0028] Figure 4 yes Figure 3 A partial enlarged view of point A in the middle;

[0029] Figure 5 yes Figure 2 Schematic diagram of the structure of the blade;

[0030] Figure 6 yes Figure 5 A partial enlarged view of point B in the middle;

[0031] Figure 7 yes Figure 2 Axial projection of the blade in ;

[0032] Figure 8 1 is a schematic diagram of the control flow of the air conditioner in the embodiment of the present invention;

[0033] Figure 9 It is a simulated cloud diagram of the flow field in the air duct of a cross-flow fan in the prior art;

[0034] Figure 10 It is a simulation cloud diagram of the flow field in the air duct of the crossflow fan in the present invention.

[0035] The accompanying drawings are:

[0036] 1. Middle section fan blade; 11. Fan blade base; 12. Blade; 121. Blade leading edge; 1211. Large tooth; 1212. Small tooth; 122. Blade trailing edge; 1221. Guide tooth; 123. Blade body; 10. Crossflow fan blade; 21. Wind guide plate; 22. Acceleration detection device; 23. Piezoelectric actuator array; 231. Piezoelectric actuator power module; 30. Drive motor; 4. Main board; 41. Vibration analysis module. DETAILED DESCRIPTION

[0037] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0040] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0041] See also Figures 1 to 10 As shown, according to an embodiment of the present invention, a cross-flow fan blade is provided, including a multi-section middle-section fan blade 1, wherein the middle-section fan blade 1 includes a fan base 11 and a plurality of blades 12 arranged at intervals around the central axis of the middle-section fan blade 1. It can be understood that the blades 12 are evenly spaced around the central axis of the middle-section fan blade 1, and the interval between two adjacent blades 12 forms a flow gap for airflow. Each of the blades 12 has a blade leading edge 121, a blade trailing edge 122, and a blade wing body 123 connected between the blade leading edge 121 and the blade trailing edge 122. The aforementioned leading edge refers to the side of the blade 12 that is closer to the radial outer circle of the middle-section fan blade 1, and the trailing edge refers to the side of the blade 12 that is closer to the central axis of the middle-section fan blade 1. The blade leading edge 121 is provided with leading edge vortex-breaking teeth (not marked in the figure) arranged at intervals along the length direction of the blade 12, and the blade trailing edge 122 is provided with trailing edge guide teeth 1221 arranged at intervals along the length direction of the blade 12.

[0042] In this technical solution, a plurality of leading edge vortex-breaking teeth are provided on the leading edge 121 of each blade 12, which can effectively decompose large-scale vortices (that is, the incoming air flow is subdivided and cut, and large vortices are decomposed into micro vortices), improve the pressure fluctuations at the turbulent boundary (that is, improve the turbulence in the air duct), and avoid excessive disturbance of the mainstream, thereby reducing the aerodynamic noise of the through-flow blade. At the same time, a plurality of trailing edge guide teeth 1221 are provided on the trailing edge 122 of each blade 12, which can further disperse the vortices gathered at the blade tip (that is, the blade trailing edge 122) due to airflow scouring, thereby suppressing vortex noise, and thus improving user comfort.

[0043] See also Figure 9 and Figure 10 As shown, by comparing the existing technical solution (without leading edge vortex breaking teeth and trailing edge guide teeth 1221) with the technical solution of the present invention (with leading edge vortex breaking teeth and trailing edge guide teeth 1221), it is found that when the steady state is reached under the same fan speed and airflow conditions, the static pressure intensity of the two shedding vortex centers at point A in the air duct flow field of the technical solution of the present invention is reduced from 46Pa to 34Pa, a decrease of about 26%, and the airflow distribution is also more uniform, thereby reducing the aerodynamic noise in the air duct; the position of the eccentric vortex center at point B is offset by about 5% toward the center axis position of the fan blade, reducing the turbulence and disturbance excited when the airflow passes through the tip of the fan blade, and reducing the aerodynamic noise generated by the fan blade.

[0044] In some embodiments, see Figure 6 As shown, the leading edge vortex-breaking teeth include a plurality of large teeth 1211 spaced apart along the length direction of the blade 12 and a plurality of small teeth 1212 between the large teeth 1211 , the tooth height of each large tooth 1211 is greater than the tooth height of each small tooth 1212 , and the tooth thickness of each large tooth 1211 is greater than the tooth thickness of each small tooth 1212 .

[0045] In this technical solution, the leading edge vortex-breaking teeth are composed of multiple large teeth 1211 and small teeth 1212, among which the large teeth 1211 can effectively suppress low-frequency noise (such as low-frequency noise generated by blade vibration) while reducing large-scale vortices in the airflow, and the small teeth 1212 can effectively suppress high-frequency noise (such as high-frequency noise generated by airflow impact and turbulence) and absorb high-frequency sound waves. The mixed use of large teeth 1211 and small teeth 1212 can achieve more comprehensive noise reduction frequency coverage and effectively reduce noise within the entire spectrum range. In addition, the mixed design of large teeth 1211 and small teeth 1212 can also optimize the smoothness of the airflow, reduce airflow separation, and further reduce noise.

[0046] In a specific embodiment shown in the figure, the number of the small teeth 1212 arranged between two adjacent large teeth 1211 is four.

[0047] In this technical solution, four small teeth 1212 are set between two large teeth 1211, which can adapt to the limited structural space on the blade and can optimize the aerodynamic performance and noise reduction performance of the blade to a certain extent. Experimental verification shows that too many small teeth 1212 will lead to increased airflow resistance and affect the efficiency of the fan. At the same time, too small a distance between the small teeth 1212 will affect the noise reduction effect, while too few small teeth 1212 cannot effectively cover high-frequency noise, cannot fully smooth the airflow, and the noise reduction effect is limited.

[0048] In a specific embodiment, the tooth height of each large tooth 1211 is 0.8±0.08 mm and the tooth width is 0.7±0.07 mm; the tooth height of each small tooth 1212 is 0.7±0.07 mm and the tooth width is 0.15±0.015 mm, the spacing between two adjacent large teeth 1211 is equal, the spacing between two adjacent small teeth 1212 is equal, and / or the spacing between two adjacent large teeth 1211 is 1.6±0.16 mm.

[0049] In some embodiments, the top end of each of the large teeth 1211 and small teeth 1212 has a rounded transition; and / or, the front and rear walls of each of the large teeth 1211 and small teeth 1212 extend along the contour lines of the front and rear walls of the blade body 123, and the front and rear walls of each large tooth 1211 and the front and rear walls of each small tooth 1212 intersect at the tooth top, which can further decompose large-scale vortices, improve pressure fluctuations at the turbulent boundary, and avoid excessive disturbance of the mainstream. It can be understood that the front walls of the large teeth 1211 and small teeth 1212 correspond to the outer wall of the blade body 123, while the rear walls correspond to the inner wall of the blade body 123.

[0050] In a specific embodiment, the tooth height of each guide tooth 1221 is 3.4±0.34 mm, the tooth width is 0.5±0.05 mm, and the tooth pitch is 0.5±0.05 mm.

[0051] In some embodiments, the front wall surface of each guide tooth 1221 extends in correspondence with the contour line of the front wall surface of the blade body 123, and the root thickness of the guide tooth 1221 is 60% of the trailing edge thickness of the blade body 123, and the rear wall surface of the root of each guide tooth 1221 is connected to the rear wall surface of the blade body 123 by a circular arc transition.

[0052] In this technical solution, the proportional relationship between the root thickness of the guide tooth 1221 and the trailing edge thickness of the blade body 123 is limited, and the connection position between the two is processed with an arc transition, which can accelerate the airflow at the end of the rear wall of the blade body 123 to enter the trailing edge guide tooth 1221, and avoid the airflow adhesion and aggregation to form secondary vortex.

[0053] According to an embodiment of the present invention, there is also provided an air conditioner, comprising a cross flow fan, wherein the cross flow fan comprises a cross flow fan blade 10, and the cross flow fan blade 10 is the cross flow fan blade described above, see Figure 2 As shown, a driving motor 30 is connected to one axial end of the cross flow blade 10 , and the driving motor 30 is used to drive the cross flow blade 10 to rotate.

[0054] See Figure 1 As shown, the air conditioner further includes an air deflector assembly (not labeled in the figure) at the air outlet of the air conditioner, and the air deflector assembly includes an air deflector 21. In conventional technology, the air deflector is disturbed by the unstable air flow and its own wind sweeping motion, which causes irregular vibration, thereby further increasing the operating noise of the air conditioner indoor unit. In order to overcome the deficiencies in the aforementioned conventional technology, in some embodiments, the air deflector assembly further includes an acceleration detection device 22 and a piezoelectric actuator array 23 (including a plurality of piezoelectric actuator units), wherein the acceleration detection device 22 is used to detect the acceleration information of the air deflector 21 during operation and Extract its vibration spectrum. The piezoelectric actuator array 23 is used to control the air guide plate 21 to produce reverse deformation. The aforementioned acceleration detection device 22 can specifically adopt a commercially available three-axis (direction) acceleration sensor. At this time, the air conditioner is correspondingly configured with a corresponding mainboard 4, and a vibration analysis module 41 is correspondingly configured on the mainboard 4. The vibration analysis module 41 is used to receive the real-time vibration spectrum of the air guide plate 21 detected and obtained by the aforementioned acceleration detection device 22, and can extract the main frequency based on the aforementioned real-time vibration spectrum (using known processing means), and then convert the spectrum signal into a corresponding voltage signal and transmit it to the piezoelectric actuator array 23 to drive the air guide plate 21 to produce reverse vibration displacement.

[0055] In this technical solution, a piezoelectric actuator array is set on the wall surface of the air guide plate 21, which can convert the input voltage signal into material deformation, thereby achieving displacement of the air guide plate 21. The acceleration detection device can extract the vibration spectrum of the air guide plate 21 at the current speed of the cross-flow fan based on the acceleration information of the air guide plate 21 during operation, extract the main frequency through the vibration analysis module, and then convert the spectrum signal into a voltage signal and transmit it to the piezoelectric actuator array to drive the air guide plate to perform reverse vibration displacement, thereby solving the aerodynamic coupling and mechanical coupling control problems of the vibration noise of the air guide plate 21 and the speed of the cross-flow fan. Combined with vibration characteristic analysis and active noise reduction technology, it is suitable for noise suppression of the air guide plate under different speed conditions of the air conditioner. It can use electromechanical control means to calculate and analyze the vibration characteristics at different speeds to ensure the reliability and adaptability of the noise reduction effect.

[0056] In a specific embodiment, the acceleration detection device 22 is disposed at the rotation axis of the wind deflector 21, and the piezoelectric actuator array 23 is disposed on the leeward side of the wind deflector 21 to reduce wind resistance to the outgoing airflow.

[0057] According to an embodiment of the present invention, there is also provided a method for controlling the air conditioner, comprising the following steps:

[0058] A target frequency f1 is obtained based on the real-time rotational speed of the crossflow blade 10, and a main frequency f2 of the vibration spectrum of the air guide plate 21 is obtained based on the acceleration detection device 22. Specifically, the target frequency f1 = n / 60, where n is the real-time rotational speed of the crossflow blade. When the drive motor 30 directly drives the crossflow blade to rotate, the real-time rotational speed is also the real-time rotational speed of the drive motor 30. The main frequency f2 of the vibration spectrum is obtained by the triaxial acceleration sensor and the vibration analysis module 41.

[0059] Determine whether f2≈kf1 or f2≈kf0 holds true, where f0 is the natural frequency of the air deflector and k=1, 2, 3, ...;

[0060] When f2≈kf1 or f2≈kf0 is established, the piezoelectric actuator array 23 is controlled to generate a reverse phase to apply a reverse displacement to the wind guide plate 21, that is, the power supply to the piezoelectric actuator power supply module 231 is controlled to make the piezoelectric actuator array 23 operate until f2≈kf1 or f2≈kf0 is not established, and the piezoelectric actuator array 23 is controlled to stop operating; when f2≈kf1 or f2≈kf0 is not established, the piezoelectric actuator array 23 is controlled not to operate.

[0061] See Figure 8As shown, when the air conditioner is turned on and running, the three-axis acceleration sensor (i.e., the aforementioned acceleration detection device 22), the piezoelectric actuator array 23, and the vibration analysis module 41 are first initialized, and the following basic parameters are determined respectively, including but not limited to: the sampling rate of the three-axis acceleration sensor (usually 1000Hz to 10000Hz to ensure that high-frequency vibrations are captured), the sensitivity (±2g to ±100g), the operating voltage range of the piezoelectric actuator power module 231 (usually 0V to 100V), the voltage of each piezoelectric actuator unit (i.e., the piezoelectric actuator array 231 ... The drive signal frequency (10 Hz to 1000 Hz) of each component in the actuator array is recorded by the vibration analysis module 41, and the natural frequency f0 of the air deflector is recorded by the vibration analysis module 41. During the continuous operation of the air conditioner, the main board 4 can obtain the speed n (unit: rpm) of the drive motor 30 and the vibration spectrum data of the air deflector 21 recorded by the three-axis acceleration sensor in real time. Through calculation and spectrum analysis, the target frequency f1 = n / 60 and the main frequency f2 of the vibration spectrum are obtained respectively, and the condition f2 ≈ kf1 or f2 ≈ kf0 (where k = 1, 2, 3, ...) is judged. If it is true, the piezoelectric actuator power supply module 231 is started, and the voltage signal and acceleration direction signal are input to each piezoelectric actuator unit, and each piezoelectric actuator unit is adjusted to generate a reverse phase, and a reverse displacement is applied to the air deflector 21. At the same time, the changes of f1 and f2 are continuously monitored until the above conditions are no longer met. If they are not met, the piezoelectric actuator power supply module 231 remains in the off state, and the main board 4 continues to calculate and analyze f1 and f2, and the above control process is repeated.

[0062] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A crossflow fan blade, comprising a plurality of intermediate section fan blades (1), characterized in that: The middle-section fan blade (1) comprises a fan blade base (11) and a plurality of blades (12) spaced apart around the central axis of the middle-section fan blade (1), each of the blades (12) comprising a blade leading edge (121), a blade trailing edge (122) and a blade wing body (123) connected between the blade leading edge (121) and the blade trailing edge (122), the blade leading edge (121) being provided with leading edge vortex-breaking teeth spaced apart along the length direction of the blade (12), and the blade trailing edge (122) being provided with trailing edge guide teeth spaced apart along the length direction of the blade (12).

2. The crossflow fan blade according to claim 1, characterized in that: The leading edge vortex-breaking teeth comprise a plurality of large teeth (1211) spaced apart along the length direction of the blade (12) and a plurality of small teeth (1212) located between the large teeth (1211), wherein the tooth height of each large tooth (1211) is greater than the tooth height of each small tooth (1212), and the tooth thickness of each large tooth (1211) is greater than the tooth thickness of each small tooth (1212).

3. The crossflow fan blade according to claim 2, characterized in that: The tooth height of each large tooth (1211) is 0.8±0.08 mm and the tooth width is 0.7±0.07 mm; the tooth height of each small tooth (1212) is 0.7±0.07 mm and the tooth width is 0.15±0.015 mm; and / or, the number of small teeth (1212) arranged between two adjacent large teeth (1211) is four.

4. The crossflow fan blade according to claim 2, characterized in that: The spacing between two adjacent large teeth (1211) is equal, and the spacing between two adjacent small teeth (1212) is equal; and / or, the spacing between two adjacent large teeth (1211) is 1.6±0.16 mm.

5. The crossflow fan blade according to claim 2, characterized in that: The tooth top end surfaces of each of the large teeth (1211) and the small teeth (1212) are rounded transitions; and / or, the front and rear walls of each of the large teeth (1211) and the small teeth (1212) extend in accordance with the contour lines of the front and rear walls of the blade body (123), and the front and rear walls of each of the large teeth (1211) and the front and rear walls of each of the small teeth (1212) intersect at the tooth tops.

6. The crossflow fan blade according to claim 1, characterized in that: The tooth height of each guide tooth (1221) is 3.4±0.34 mm, the tooth width is 0.5±0.05 mm, and the tooth pitch is 0.5±0.05 mm; and / or the front wall surface of each guide tooth (1221) extends in correspondence with the profile line of the front wall surface of the blade body (123), and the tooth root thickness of the guide tooth (1221) is 60% of the trailing edge thickness of the blade body (123).

7. The crossflow fan blade according to claim 6, characterized in that: The tooth root rear wall surface of each guide tooth (1221) is connected to the rear wall surface of the blade body (123) in a circular arc transition.

8. An air conditioner comprising a cross-flow fan, wherein the cross-flow fan comprises a cross-flow fan blade (10), characterized in that: The crossflow fan blade (10) is the crossflow fan blade according to any one of claims 1 to 7.

9. The air conditioner according to claim 8, characterized in that The invention also includes an air deflector assembly located at the air outlet of the air conditioner, wherein the air deflector assembly includes an air deflector (21), an acceleration detection device (22), and a piezoelectric actuator array (23), wherein the acceleration detection device (22) is used to detect the acceleration information of the air deflector (21) in real time when the air deflector (21) is in operation and extract its vibration spectrum, and the piezoelectric actuator array (23) is used to control the air deflector (21) to produce reverse deformation.

10. The air conditioner according to claim 9, characterized in that The acceleration detection device (22) is arranged at the rotation axis of the wind deflector (21), and the piezoelectric actuator array (23) is arranged on the leeward side of the wind deflector (21); and / or the acceleration detection device (22) is a three-axis acceleration sensor.

11. A method for controlling an air conditioner according to claim 9 or 10, characterized in that: The steps include: Obtaining a target frequency f1 based on the real-time rotation speed of the crossflow blade (10) and obtaining a vibration spectrum main frequency f2 of the air guide plate (21) based on the acceleration detection device (22); It is determined whether f2≈kf1 or f2≈kf0 is established, wherein f0 is the natural frequency of the air guide plate, and k=1, 2, 3, ...; when f2≈kf1 or f2≈kf0 is established, the piezoelectric actuator array (23) is controlled to generate a reverse phase to apply a reverse displacement to the air guide plate (21), and the piezoelectric actuator array (23) is controlled to stop operating when f2≈kf1 or f2≈kf0 is not established.

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