Rear guide vane assembly, axial flow fan and air conditioner

Abstract

The utility model provides a rear guide vane assembly, an axial flow fan and an air conditioner. The rear guide vane assembly comprises an air guide cap; and all the profiling guide vanes are annularly distributed by taking the air guide cap as the center. According to the rear guide vane assembly, the axial flow fan and the air conditioner, the blade grid inlet airflow angle and the blade grid outlet airflow angle of the profiling guide vane are used for controlling the mean camber line of the profiling guide vane, so that the profiling guide vane can rotate deflection airflow back to the axial direction to the maximum extent according to different speed areas; the cross section of the profiling guide vane controlled by the blade grid inlet airflow angle and / or the blade grid outlet airflow angle of the profiling guide vane can conform to the wing-shaped cross section shape of a sea gull wing, and the sea gull wing has the characteristics of high lift coefficient and high lift-drag ratio, so that the working efficiency of the axial flow fan is improved. Compared with a traditional rear guide vane, the profiling guide vane has more excellent aerodynamic performance, and the aerodynamic performance of the rear guide vane assembly and the axial flow fan can be remarkably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air treatment equipment, in particular to a rear guide vane assembly, an axial flow fan and an air conditioner. Background Art

[0002] With the gradual popularization of air conditioners, as a major part of building energy consumption, the energy consumption problem of air conditioners cannot be ignored. At the same time, with the improvement of people's living standards, the air conditioner noise level has gradually become an important factor for people to choose air conditioner products. The performance of the fan is an important factor affecting the energy consumption and noise level of the air conditioner. How to optimize the performance such as the air volume and noise of the fan at a certain rotational speed and size has become a key issue in the development of air conditioners.

[0003] In high-speed axial flow fans, the rear guide vane structure is an effective solution to improve the performance and efficiency of the fan without increasing energy consumption. The rear guide vane structure changes the rotation direction of the air flow, swirls the deflected air flow flowing through the fan impeller back to the axial direction, and at the same time converts the kinetic energy of the deflected air flow into static pressure energy, thereby improving the working efficiency of the fan. However, in the prior art, when a rear guide vane structure is arranged in an axial flow fan, the blade design usually adopts a straight blade shape (that is, the blade stacking line is perpendicular to the hub surface), and the middle arc of the blade generally selects a single circular arc to reduce the air flow swirling speed and convert part of the kinetic energy into pressure energy. The blade profiles at the top and the root are the same. After the tip clearance vortex detaches from the suction surface of the blade, it impacts the rear guide vane and causes flow separation on the pressure surface of the rear guide vane, seriously affecting the working efficiency of the axial flow fan. Summary of the Utility Model

[0004] In order to solve the technical problem that the unreasonable blade shape of the rear guide vane in the prior art causes poor working efficiency of the axial flow fan, a rear guide vane assembly, an axial flow fan and an air conditioner are provided, which control the middle arc of the profiled guide vane by using the inlet air flow angle and / or the outlet air flow angle of the guide vane cascade of the profiled guide vane to improve the working efficiency of the axial flow fan.

[0005] A rear guide vane assembly includes:

[0006] A wind guide cap;

[0007] A plurality of profiled guide vanes, all of the profiled guide vanes are annularly distributed with the wind guide cap as the center;

[0008] The variation formula of the inlet air flow angle α of the guide vane cascade of the profiled guide vane is:

[0009] α = α0 + k1 * V1;

[0010] where α0 is the set initial value at the inlet, k1 is a calculation constant, and V1 is the wind speed at the inlet of the profiled guide vane;

[0011] The variation formula for the flow angle β at the cascade outlet of the profiling guide vane is as follows:

[0012] β = β0 + k2 * V2;

[0013] Where β0 is the initial value set at the inlet, k2 is a calculation constant, and V2 is the wind speed at the outlet of the profiling guide vane.

[0014] The calculation formulas for the wind speed V1 at the inlet of the profiling guide vane and the wind speed V2 at the outlet of the profiling guide vane are as follows:

[0015] V = g1z 4 + g2z 3 + g3z 2 + g4z;

[0016] Where g1, g2, g3, and g4 are calculation constants, z is the radius at different radial positions of the air inlet where the rear guide vane assembly is located, and the value range of z is from 0 to R, where R is the radius of the air inlet.

[0017] The value of g1 is -5881.1 ± 0.0512; and / or, the value of g2 is 4864.3 ± 0.02216; and / or, the value of g3 is 2332.4 ± 0.1453; the value of g4 is 692.04 ± 0.0015.

[0018] The fitting formula for the pressure side profile line of the profiling guide vane is:

[0019] y1 = m1x5 + m2x4 + m3x3 + m4x2 + m5x + M;

[0020] Where m1, m2, m3, m4, m5, and M are calculation constants, x is the abscissa of the pressure side of the profiling guide vane, and y1 is the ordinate of the pressure side of the profiling guide vane.

[0021] The value of m1 is -0.00001 ± 2.121E-6; and / or, the value of m2 is -0.001 ± 3.4125E-4; and / or, the value of m3 is -0.024 ± 2.11E-4; and / or, the value of m4 is -0.313 ± 0.0018; and / or, the value of m5 is 2.0684 ± 1.2E-4; and / or, the value of M is -0.2707 ± 1.23E-4.

[0022] The fitting formula for the suction side profile line of the profiling guide vane is:

[0023] y2 = n1x 3 + n2x 2 + n3x + N;

[0024] Among them, n1, n2, n3, and M are calculation constants, x is the abscissa of the suction side of the profiling guide vane, and y2 is the ordinate of the suction side of the profiling guide vane.

[0025] The value of n1 is 0.00004 ± 2.34E-6; and / or, the value of n2 is -0.0166 ± 0.000136; and / or, the value of n3 is 0.4708 ± 0.0001; and / or, the value of N is 1.0878 ± 0.000224.

[0026] The value range of k1 is -0.1 ≤ k1 ≤ -0.2; and / or, the value range of k2 is -0.15 ≤ k2 ≤ -0.25; and / or, the numerical range of α0 is 30° to 50°; and / or, the numerical range of β0 is 40° to 60°.

[0027] The airfoil of the profiling guide vane is the sectional airfoil at A% from the wing root of the imitation seagull wing, where the value range of A is 40 < A ≤ 50.

[0028] A first noise reduction structure is provided on the profiling guide vane.

[0029] Noise reduction teeth are provided on the edge corresponding to the outlet of the profiling guide vane, and the noise reduction teeth constitute the first noise reduction structure.

[0030] The shape formula of the noise reduction teeth is:

[0031] y = fsin bx;

[0032] Among them, y is the ordinate of the noise reduction teeth; x is the abscissa of the noise reduction teeth; f is the waveform amplitude; b is the angular frequency.

[0033] The calculation formula of the angular frequency is:

[0034] b = 2πc / λ;

[0035] Among them, λ is the wavelength; c is the chord length of the profiling guide vane.

[0036] The value range of the wavelength λ is 0.15c ≤ λ ≤ 0.5c; and / or, the value range of the waveform amplitude is 0.05c ≤ f ≤ 0.1c.

[0037] A first installation area is formed on the profiling guide vane, the wind speed at the first installation area is greater than 30% of the average wind speed of the cross-section where the rear guide vane assembly is located, and the first noise reduction structure is arranged at the first installation area; and / or, along the length direction of the profiling guide vane, the distance from the first noise reduction structure to the air deflector is in the range of 0.45L to 0.85L, where L is the length of the profiling guide vane.

[0038] A second noise reduction structure is provided on the portion of the profiling guide vane away from the air guide cap.

[0039] A plurality of noise reduction grooves are provided on the pressure side surface of the portion of the profiling guide vane away from the air guide cap, and all the noise reduction grooves constitute the second noise reduction structure.

[0040] Along the direction from the inlet of the profiling guide vane to the outlet of the profiling guide vane, the distance between two adjacent noise reduction grooves gradually increases.

[0041] The numerical range of the diameter d of the noise reduction groove is 0.8 mm ≤ d ≤ 1.6 mm; and / or, the numerical range of the depth h of the noise reduction groove is 1.2d ≤ h ≤ 2.1d, where d is the diameter of the noise reduction groove; and / or, along the width direction of the profiling guide vane, the numerical range of the minimum distance s1 between two adjacent noise reduction grooves is d ≤ s1 ≤ 2d, where d is the diameter of the noise reduction groove; and / or, along the length direction of the profiling guide vane, the numerical range of the minimum distance s2 between two adjacent noise reduction grooves is d ≤ s2 ≤ 10d.

[0042] The profiling guide vane has a second end away from the air guide cap, and the second noise reduction structure is located within the range from the second end to a distance of 1 / 10r from the second end, where r is the radius of the rotating air blade corresponding to the rear guide vane assembly.

[0043] The rear guide vane assembly further includes an air guide ring, the air guide cap is disposed within the air guide ring, the profiling guide vane is disposed between the air guide cap and the air guide ring, and one end of the profiling guide vane away from the air guide cap is disposed on the air guide ring.

[0044] An axial flow fan includes the above-mentioned rear guide vane assembly.

[0045] The axial flow fan further includes a housing and a rotating air blade, the rotating air blade is rotatably disposed within the housing, the rear guide vane assembly is disposed within the housing, and the rear guide vane assembly is located on the outflow side of the rotating air blade.

[0046] An air conditioner includes the above-mentioned rear guide vane assembly or the above-mentioned axial flow fan.

[0047] The post-guide vane assembly, axial-flow fan and air conditioner provided by the present utility model utilize the inlet air flow angle and outlet air flow angle of the cascade of the profile-guided vane to control the mean camber line of the profile-guided vane, so that the profile-guided vane can swirl the deflected air flow back to the axial direction to the greatest extent for different speed regions, thereby improving the working efficiency of the axial-flow fan. Moreover, the cross-section of the profile-guided vane controlled by the inlet air flow angle and / or outlet air flow angle of the cascade of the profile-guided vane can conform to the airfoil cross-section shape of a seagull wing. Since the seagull airfoil has the characteristics of a high lift coefficient and a high lift-drag ratio, the profile-guided vane of the present application has better aerodynamic performance compared with the traditional post-guide vane, and can significantly enhance the aerodynamic performance of the post-guide vane assembly and the axial-flow fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a schematic structural diagram of a post-guide vane assembly provided by an embodiment of the present utility model;

[0049] Figure 2 is a schematic diagram of the airfoil cross-section of a profile-guided vane provided by an embodiment of the present utility model;

[0050] Figure 3 is a partial schematic diagram of a profile-guided vane provided by an embodiment of the present utility model;

[0051] Figure 4 is another partial schematic diagram of a profile-guided vane provided by an embodiment of the present utility model;

[0052] Figure 5 is a schematic diagram of the shape of a noise reduction tooth provided by an embodiment of the present utility model;

[0053] Figure 6 is a fitting curve graph of the pressure side profile line and the suction side profile line of a profile-guided vane provided by an embodiment of the present utility model;

[0054] Figure 7 is a wind speed distribution diagram at the cross-section where the post-guide vane assembly is located provided by an embodiment of the present utility model;

[0055] Figure 8 is a schematic structural diagram of an axial-flow fan provided by an embodiment of the present utility model;

[0056] Figure 9 is another schematic structural diagram of an axial-flow fan provided by an embodiment of the present utility model;

[0057] In the figure:

[0058] 1, air guide cap; 2, profile-guided vane; 3, noise reduction tooth; 4, noise reduction groove; 5, air guide ring; 6, rotating wind blade; 21, pressure side profile line; 22, suction side profile line. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] In order to make the objectives, technical solutions and advantages of the present utility model more clearly understood, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0060] In order to enable those skilled in the art of this technology to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0061] It should be noted that the terms "first", "second", etc. in the description and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances for the embodiments of the present utility model described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0062] It should be noted that in the description of the present utility model, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0063] In addition, it should also be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0064] In high-speed axial fans, the rear guide vane structure is an effective solution to improve the performance and efficiency of the fan without increasing energy consumption. The rear guide vane structure changes the rotation direction of the air flow, swirls the deflected air flow passing through the fan impeller back to the axial direction, and at the same time converts the kinetic energy of the deflected air flow into static pressure energy, thereby improving the working efficiency of the fan. However, in the prior art, when setting the rear guide vane structure in an axial fan, the blade design usually adopts a straight blade shape (that is, the blade stacking line is perpendicular to the hub surface). The middle arc of the blade generally selects a single arc to reduce the air flow swirling speed and convert part of the kinetic energy into pressure energy. The blade profiles at the top and root are the same. After the tip clearance vortex detaches from the suction surface of the blade, it impacts the rear guide vane and causes flow separation on the pressure surface of the rear guide vane, seriously affecting the working efficiency of the axial fan. Therefore, this application provides a rear guide vane assembly as shown in Figures 1 to 9 which includes: a wind guiding cap 1; a plurality of profile-following guide vanes 2, and all the profile-following guide vanes 2 are annularly distributed with the wind guiding cap 1 as the center; the variation formula of the inlet air flow angle α of the cascade of the profile-following guide vane 2 is:

[0065] α = α0 + k1 * V1;

[0066] wherein, α0 is the set initial value at the inlet, k1 is a calculation constant, and V1 is the wind speed at the inlet of the profile-following guide vane 2;

[0067] The variation formula of the outlet air flow angle β of the cascade of the profile-following guide vane 2 is:

[0068] β = β0 + k2 * V;

[0069] wherein, β0 is the set initial value at the inlet, k2 is a calculation constant, and V is the wind speed at the cross-section where the rear guide vane assembly is located.

[0070] The middle arc of the profile-following guide vane 2 is controlled by using the inlet air flow angle and the outlet air flow angle of the cascade of the profile-following guide vane 2, so that the profile-following guide vane 2 can swirl the deflected air flow back to the axial direction to the greatest extent for different speed regions, thereby improving the working efficiency of the axial fan. The cross-section of the profile-following guide vane 2 controlled by the inlet air flow angle and / or the outlet air flow angle of the cascade of the profile-following guide vane 2 can conform to the airfoil cross-section shape of a seagull wing. Since the seagull airfoil has the characteristics of a high lift coefficient and a high lift-to-drag ratio, the profile-following guide vane 2 of this application has better aerodynamic performance compared with the traditional rear guide vane, and can significantly enhance the aerodynamic performance of the rear guide vane assembly and the axial fan. The inlet air flow angle α of the cascade refers to the included angle between the relative air flow velocity at the inlet of the profile-following guide vane 2 and the frontal line of the cascade, and the outlet air flow angle β of the cascade refers to the included angle between the relative air flow velocity at the outlet of the profile-following guide vane 2 and the frontal line of the cascade.

[0071] Among them, the value range of k1 is -0.1 ≤ k1 ≤ -0.2. Preferably, the value of k1 is -0.15.

[0072] The value range of k2 is -0.15 ≤ k2 ≤ -0.25. Preferably, the value of k2 is -0.18.

[0073] The value range of α0 is from 30° to 50°. By limiting the initial value α0 at the inlet, the basic inclination angle of the profiling guide vane 2 is ensured, which guarantees the deflection ability of the profiling guide vane 2 for the air flow and the improvement of the fan performance and efficiency by the rear guide vane assembly. Among them, the angle of the air flow at the inlet of the cascade of the end where the profiling guide vane 2 is connected to the air guide cap 1 is α0. Preferably, the value of α0 is 40°.

[0074] The value range of β0 is from 40° to 60°. By limiting the initial value β0 at the outlet, the basic inclination angle of the profiling guide vane 2 is ensured, which guarantees the deflection ability of the profiling guide vane 2 for the air flow and the improvement of the fan performance and efficiency by the rear guide vane assembly. Among them, the angle of the air flow at the outlet of the cascade of the end where the profiling guide vane 2 is connected to the air guide cap 1 is β0. Preferably, the value of β0 is 50°.

[0075] The calculation formulas for the wind speed V1 at the inlet of the profiling guide vane 2 and the wind speed V2 at the outlet of the profiling guide vane 2 are as follows:

[0076] V = g1z 4 + g2z 3 + g3z 2 + g4z;

[0077] Among them, g1, g2, g3, and g4 are calculation constants, z is the radius at different radial positions of the air outlet where the rear guide vane assembly is located, and the value range of z is from 0 to R, where R is the radius of the air outlet. According to the velocity distribution nephogram of the cross-section corresponding to the rear guide vane assembly, the velocity distribution law of this cross-section is determined, and then the velocity curve is fitted to the velocity distribution law of this cross-section according to the above formula. Thus, V1 and V2 corresponding to each profiling guide vane 2 can be calculated according to this velocity curve, and finally, the inlet air flow angle α and the outlet air flow angle β of the cascade of each profiling guide vane 2 can be obtained. Finally, the middle arc of the profiling guide vane 2 can be determined, so that the profiling guide vane 2 can deflect the air flow back to the axial direction to the greatest extent for different velocity regions, thereby improving the working efficiency of the axial flow fan. As Figure 7 shown, the abscissa is x and the ordinate is V.

[0078] Optionally, the value of g1 is -5881.1 ± 0.0512.

[0079] The value of g2 is 4864.3 ± 0.02216.

[0080] The value of g3 is 2332.4 ± 0.1453.

[0081] The value of g4 is 692.04 ± 0.0015.

[0082] After determining the inlet air flow angle and the outlet air flow angle of the cascade of the profiling guide vane 2, the mean camber line of the profiling guide vane 2 is obtained. Then, the profiling guide vane 2 is reversely reconstructed in combination with the airfoil section shape of the seagull wing, the profile line coordinates of the profiling guide vane 2 are determined, and a fitting function is used for fairing processing. For the pressure side profile line, the fitting formula of the pressure side profile line 21 of the profiling guide vane 2 is:

[0083] y1 = m1x 5 + m2x 4 + m3x 3 + m4x 2 + m5x + M;

[0084] Among them, m1, m2, m3, m4, m5, and M are calculation constants, x is the abscissa of the pressure side of the profiling guide vane 2, and y1 is the ordinate of the pressure side of the profiling guide vane 2.

[0085] The value of m1 is -0.00001 ± 2.121E-6.

[0086] The value of m2 is -0.001 ± 3.4125E-4.

[0087] The value of m3 is -0.024 ± 2.11E-4.

[0088] The value of m4 is -0.313 ± 0.0018.

[0089] The value of m5 is 2.0684 ± 1.2E-4.

[0090] The value of M is -0.2707 ± 1.23E-4.

[0091] For the suction side profile line, the fitting formula of the suction side profile line 22 of the profiling guide vane 2 is:

[0092] y2 = n1x 3 + n2x 2 + n3x + N;

[0093] Among them, n1, n2, n3, and M are calculation constants, x is the abscissa of the suction side of the profiling guide vane 2, and y2 is the ordinate of the suction side of the profiling guide vane 2.

[0094] The value of n1 is 0.00004 ± 2.34E-6.

[0095] The value of n2 is -0.0166 ± 0.000136.

[0096] The value of n3 is 0.4708 ± 0.0001.

[0097] The value of N is 1.0878 ± 0.000224.

[0098] By defining the pressure side profile line 21 and the suction side profile line 22 of the profiling guide vane 2, the profiling guide vane 2 can conform to the airfoil section shape of the seagull wing. At this time, the profiling guide vane 2 can have the characteristics of a high lift coefficient and a high lift-to-drag ratio of the seagull airfoil, making the profiling guide vane 2 of the present application have better aerodynamic performance compared with the traditional trailing guide vane, and can significantly enhance the aerodynamic performance of the trailing guide vane assembly and the axial flow fan. As Figure 6 shown, the triangles in the figure are the pressure side coordinate points, the dashed line where the triangles are located is the fitting curve of the pressure side profile line, the squares are the suction side coordinate points, and the dashed line where the squares are located is the fitting curve of the suction side profile line.

[0099] The airfoil of the profiling guide vane 2 is the cross-sectional airfoil at A% from the wing root of the seagull wing. Among them, the value range of A is 40 < A ≤ 50. Within this range, the thickness change of the airfoil section shape is large, the contour is obvious, and it is also the main lift part for the seagull to support itself. It is greatly impacted by the airflow and has the characteristics of a high lift coefficient and a high lift-to-drag ratio. The profiling guide vane 2 of the present application profiles the airfoil section shape of the seagull wing within this range, and has better aerodynamic performance compared with the traditional trailing guide vane, and can significantly enhance the aerodynamic performance of the trailing guide vane assembly and the axial flow fan. Preferably, the value of A is 45. The cross-sectional airfoil at 45% from the wing root of the seagull wing has better characteristics of a high lift coefficient and a high lift-to-drag ratio, so that the profiling guide vane 2 of the present application can have better aerodynamic performance compared with the traditional trailing guide vane, and can significantly enhance the aerodynamic performance of the trailing guide vane assembly and the axial flow fan.

[0100] When the air flow passes through the trailing guide vane, due to the laminar boundary layer vortex shedding phenomenon at the trailing edge of the guide vane, the tip clearance vortex impacts the guide vane after detaching from the suction surface of the blade, and the outflow noise generated by the contact between the guide vane and the turbulence makes aerodynamic noise generated at the outlet edge of the trailing guide vane. For this reason, a first noise reduction structure is provided on the profiling guide vane 2 in the present application. The first noise reduction structure is used to suppress the aerodynamic noise, thereby effectively reducing the aerodynamic noise of the trailing guide vane assembly and the axial flow fan.

[0101] As an implementation manner, noise reduction teeth 3 are provided on the edge corresponding to the outlet of the profiling guide vane 2. The noise reduction teeth 3 constitute the first noise reduction structure, and the noise reduction teeth 3 are used to cut the air flow flowing to the outlet edge of the profiling guide vane 2, improve the contact and collision between the profiling guide vane 2 and the turbulence, and reduce the aerodynamic noise.

[0102] The shape formula of the noise reduction teeth 3 is:

[0103] y = fsin bx;

[0104] Wherein, y is the ordinate of the noise reduction tooth 3; x is the abscissa of the noise reduction tooth 3; f is the waveform amplitude; b is the angular frequency, that is, designing the noise reduction tooth 3 as a sine waveform can be effective.

[0105] The calculation formula of the angular frequency is:

[0106] b = 2πc / λ;

[0107] Wherein, λ is the wavelength; c is the chord length of the profiling guide vane 2.

[0108] The value range of the wavelength λ is 0.15c ≤ λ ≤ 0.5c.

[0109] The value range of the waveform amplitude is 0.05c ≤ f ≤ 0.1c;

[0110] When the values of the wavelength λ and the waveform amplitude f are within the above value ranges, the sine shape of the noise reduction tooth can significantly change the airflow state of the high-speed rotating airflow flowing through the boundary layer of the surface of the profiling guide vane, suppress the airflow vortex shedding, thereby reducing the outflow noise generated by the contact between the profiling guide vane and the turbulence. When the values of the wavelength λ and the waveform amplitude f are outside the above value ranges, the noise reduction effect of the noise reduction tooth is poor.

[0111] A first installation area is formed on the profiling guide vane 2. The wind speed at the first installation area is greater than 30% of the average wind speed of the cross-section where the rear guide vane assembly is located. The first noise reduction structure is arranged at the first installation area, as much as possible retaining the geometric characteristics of the profile of the profiling guide vane 2, while effectively reducing the outflow noise generated by the contact between the profiling guide vane 2 and the turbulence, and reducing the aerodynamic noise.

[0112] Along the length direction of the profiling guide vane 2, the distance range from the first noise reduction structure to the air guide cap 1 is 0.45L to 0.85L, where L is the length of the profiling guide vane 2. That is, the range of the first installation area on the profiling guide vane 2 is within the range of 0.45L to 0.85L from the air guide cap 1 on the profiling guide vane 2. Setting the first noise reduction structure within this distance range can effectively reduce the outflow noise generated by the contact between the profiling guide vane 2 and the turbulence, and reduce the aerodynamic noise.

[0113] Due to the existence of tip leakage eddy currents in the rotating wind blade 6 corresponding to the rear guide vane assembly, a second noise reduction structure is provided on the part of the profiling guide vane 2 away from the air guide cap 1. The second noise reduction structure is used to reduce the intensity of the leakage eddy currents of the rotating wind blade 6 and suppress the phenomenon of vortex shedding at the trailing edge of the rotating wind blade 6, thereby being able to further reduce the aerodynamic noise of the axial flow fan.

[0114] As an implementation manner, a plurality of noise reduction grooves 4 are arranged on the pressure side surface of the part of the profiling guide vane 2 away from the air guide cap 1, and all the noise reduction grooves 4 constitute the second noise reduction structure. Airflow can flow into the noise reduction grooves 4 to form microjets, which can destroy the separation blocks in the airflow, thereby attenuating the aerodynamic load fluctuations on the pressure side surface of the profiling guide vane 2 and achieving the purpose of noise reduction.

[0115] Along the direction from the inlet of the profiling guide vane 2 to the outlet of the profiling guide vane 2, the distance between two adjacent noise reduction grooves 4 along the length direction of the profiling guide vane 2 gradually increases. As the airflow flows on the profiling guide vane 2, the noise reduction grooves 4 will gradually attenuate the aerodynamic load fluctuations. Therefore, the distance between the noise reduction grooves 4 can be increased to adjust the position and quantity of the noise reduction grooves 4. On the premise of ensuring noise reduction, the quantity of the noise reduction grooves 4 can be reduced to improve the structural strength of the profiling guide vane 2.

[0116] The numerical range of the diameter d of the noise reduction groove 4 is 0.8 mm ≤ d ≤ 1.6 mm. When the diameter d of the noise reduction groove 4 is too large, it will seriously affect the structural strength of the profiling guide vane 2 and also reduce the performance of the axial flow fan where the rear guide vane assembly is located. When the diameter d is too small, the noise reduction groove 4 cannot achieve the noise reduction effect. Only when 0.8 mm ≤ d ≤ 1.6 mm can the structural strength and noise reduction requirements of the profiling guide vane 2 be satisfied simultaneously.

[0117] The numerical range of the depth h of the noise reduction groove 4 is 1.2d ≤ h ≤ 2.1d, where d is the diameter of the noise reduction groove 4. When the depth h is too large, the noise reduction groove 4 will affect the structural strength of the profiling guide vane 2 and the noise reduction effect will be significantly reduced. When the depth h is too small, the depth of the noise reduction groove 4 cannot form microjets to destroy the separation blocks in the airflow, and the noise reduction effect will also be significantly reduced. Only when 1.2d ≤ h ≤ 2.1d can the structural strength and noise reduction requirements of the profiling guide vane 2 be satisfied simultaneously.

[0118] Along the width direction of the profiling guide vane 2, the numerical range of the minimum distance s1 between two adjacent noise reduction grooves 4 is d ≤ s1 ≤ 2d, where d is the diameter of the noise reduction groove 4. When the minimum distance s1 is too large, the noise reduction groove 4 cannot achieve the noise reduction effect. When the minimum distance s1 is too small, it will seriously affect the structural strength of the profiling guide vane 2 and also reduce the performance of the axial flow fan where the rear guide vane assembly is located. Only when d ≤ s1 ≤ 2d can the structural strength and noise reduction requirements of the profiling guide vane 2 be satisfied simultaneously.

[0119] Along the length direction of the profiling guide vane 2, the numerical range of the minimum spacing s2 between two adjacent noise reduction grooves 4 is d ≤ s2 ≤ 10d. When the minimum spacing s2 is too large, the noise reduction grooves 4 cannot achieve the noise reduction effect, and when the minimum spacing s2 is too small, it will seriously affect the structural strength of the profiling guide vane 2 and also reduce the performance of the axial flow fan where the rear guide vane assembly is located. Only when d ≤ s2 ≤ 10d can the structural strength and noise reduction requirements of the profiling guide vane 2 be satisfied simultaneously.

[0120] The profiling guide vane 2 has a second end away from the air guide cap 1, and the second noise reduction structure is located within the range from the second end to a distance of 1 / 10r from the second end, where r is the radius of the rotating air blade 6 corresponding to the rear guide vane assembly. The second noise reduction structure within this range can effectively reduce the intensity of the leakage eddy current of the rotating air blade 6 and inhibit the phenomenon of the shedding of the trailing edge eddy current of the rotating air blade 6, thereby further reducing the aerodynamic noise of the axial flow fan and also reducing the influence on the structural strength of the profiling guide vane 2 when the second noise reduction structure is arranged at other positions of the profiling guide vane 2, and improving the structural reliability of the rear guide vane assembly and the axial flow fan.

[0121] The rear guide vane assembly further includes an air guide ring 5. The air guide cap 1 is arranged within the air guide ring 5, the profiling guide vane 2 is arranged between the air guide cap 1 and the air guide ring 5, and one end of the profiling guide vane 2 away from the air guide cap 1 is arranged on the air guide ring 5. The outer end of the profiling guide vane 2 is fixed by using the air guide ring 5 to ensure the reliable fixation of the position of the profiling guide vane 2, and the rear guide vane assembly can also be arranged in the corresponding axial flow fan through the air guide ring 5.

[0122] An axial flow fan includes the above-mentioned rear guide vane assembly.

[0123] The axial flow fan further includes a housing and a rotating air blade 6. The rotating air blade 6 is rotatably arranged within the housing, the rear guide vane assembly is arranged within the housing, and the rear guide vane assembly is located on the outflow side of the rotating air blade 6. Among them, the pressure side surface of the profiling guide vane 2 faces the rotating air blade 6.

[0124] An air conditioner includes the above-mentioned rear guide vane assembly or the above-mentioned axial flow fan.

[0125] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A rear guide vane assembly, characterized in that: include: Air guide cap (1); A plurality of contoured guide vanes (2), all of the contoured guide vanes (2) being distributed in a ring shape with the air guide cap (1) as the center; The formula for changing the airflow angle α of the cascade inlet of the contoured guide vane (2) is: α=α0+k1*V1; Wherein, α0 is the initial value set at the inlet, k1 is a calculation constant, and V1 is the wind speed at the inlet of the contoured guide vane (2); The formula for changing the airflow angle β at the cascade outlet of the contoured guide vane (2) is: β=β0+k2*V2; Wherein, β0 is the initial value set at the outlet, k2 is a calculation constant, and V2 is the wind speed at the outlet of the contoured guide vane (2).

2. The rear guide vane assembly according to claim 1, characterized in that: The calculation formulas for the wind speed V1 at the inlet of the contoured guide vane (2) and the wind speed V2 at the outlet of the contoured guide vane (2) are: V = g1z4 + g2z3 + g3z2 + g4z; Among them, g1, g2, g3, and g4 are calculation constants, z is the radius of the air outlet at different radial positions where the rear guide vane assembly is located, the value range of z is 0 to R, and R is the radius of the air outlet.

3. The rear guide vane assembly according to claim 2, characterized in that: The value of g1 is -5881.1±0.0512; and / or, the value of g2 is 4864.3±0.02216; and / or, the value of g3 is 2332.4±0.1453; the value of g4 is 692.04±0.0015.

4. The rear guide vane assembly according to claim 1, characterized in that: The fitting formula of the pressure side profile (21) of the contoured guide vane (2) is: y1=m1x 5 +m2x 4 +m3x 3 +m4x 2 +m5x+M; Among them, m1, m2, m3, m4, m5, and M are calculation constants, x is the abscissa of the pressure side of the contoured guide vane (2), and y1 is the ordinate of the pressure side of the contoured guide vane (2).

5. The rear guide vane assembly according to claim 4, characterized in that: The value of m1 is -0.00001±2.121E-6; and / or, the value of m2 is -0.001±3.4125E-4; and / or, the value of m3 is -0.024±2.11E-4; and / or, the value of m4 is -0.313±0.0018; and / or, the value of m5 is 2.0684±1.2E-4; and / or, the value of M is -0.2707±1.23E-4.

6. The rear guide vane assembly according to claim 1, characterized in that: The fitting formula of the suction side profile line (22) of the contoured guide vane (2) is: y2=n1x 3 +n2x 2 +n3x+N; Among them, n1, n2, n3, and M are calculation constants, x is the abscissa of the suction side of the contoured guide vane (2), and y2 is the ordinate of the suction side of the contoured guide vane (2).

7. The rear guide vane assembly according to claim 6, characterized in that: The value of n1 is 0.00004±2.34E-6; and / or, the value of n2 is -0.0166±0.000136; and / or, the value of n3 is 0.4708±0.0001; and / or, the value of N is 1.0878±0.000224.

8. The rear guide vane assembly according to claim 1, characterized in that: The value range of k1 is -0.1≤k1≤-0.2; and / or, the value range of k2 is -0.15≤k2≤-0.25; and / or, the value range of α0 is 30° to 50°; and / or, the value range of β0 is 40° to 60°.

9. The rear guide vane assembly according to claim 1, characterized in that: The airfoil of the contoured guide vane (2) is a cross-sectional airfoil shape imitating a seagull wing at a distance A% from the wing root, wherein the value range of A is 40<A≤50.

10. The rear guide vane assembly according to claim 1, characterized in that: The contoured guide vane (2) is provided with a first noise reduction structure.

11. The rear guide vane assembly according to claim 10, characterized in that: Noise reduction teeth (3) are arranged on the edge corresponding to the outlet of the contoured guide vane (2), and the noise reduction teeth (3) constitute the first noise reduction structure.

12. The rear guide vane assembly according to claim 11, characterized in that: The shape formula of the noise reduction tooth (3) is: y = fsinbx; Among them, y is the ordinate of the noise reduction tooth (3); x is the abscissa of the noise reduction tooth (3); f is the waveform amplitude; and b is the angular frequency.

13. The rear guide vane assembly according to claim 12, characterized in that: The calculation formula of the angular frequency is: b = 2πc / λ; Wherein, λ is the wavelength; c is the chord length of the contoured guide vane (2).

14. The rear guide vane assembly according to claim 13, characterized in that: The wavelength λ has a value range of 0.15c≤λ≤0.5c; and / or the waveform amplitude has a value range of 0.05c≤f≤0.1c.

15. The trailing guide vane assembly according to claim 10, characterized in that: A first installation area is formed on the contoured guide vane (2), the wind speed at the first installation area is greater than 30% of the average wind speed of the cross section where the rear guide vane assembly is located, and the first noise reduction structure is arranged at the first installation area; and / or, along the length direction of the contoured guide vane (2), the distance from the first noise reduction structure to the air guide cap (1) ranges from 0.45L to 0.85L, where L is the length of the contoured guide vane (2).

16. The trailing guide vane assembly according to claim 1, characterized in that: A second noise reduction structure is provided on the portion of the contoured guide vane (2) away from the air guide cap (1).

17. The rear guide vane assembly according to claim 16, characterized in that: A plurality of noise reduction grooves (4) are arranged on the pressure side surface of the portion of the contoured guide vane (2) away from the wind guide cap (1), and all of the noise reduction grooves (4) constitute the second noise reduction structure.

18. The rear guide vane assembly according to claim 17, characterized in that: Along the direction from the inlet of the contoured guide vane (2) to the outlet of the contoured guide vane (2), the distance between two adjacent noise reduction grooves (4) along the length direction of the contoured guide vane (2) gradually increases.

19. The trailing guide vane assembly according to claim 17, characterized in that: The diameter d of the noise reduction groove (4) has a numerical range of 0.8 mm ≤ d ≤ 1.6 mm; and / or the depth h of the noise reduction groove (4) has a numerical range of 1.2 d ≤ h ≤ 2.1 d, where d is the diameter of the noise reduction groove (4); and / or the minimum spacing s1 between two adjacent noise reduction grooves (4) along the width direction of the contoured guide vane (2) has a numerical range of d ≤ s1 ≤ 2 d, where d is the diameter of the noise reduction groove (4); and / or the minimum spacing s2 between two adjacent noise reduction grooves (4) along the length direction of the contoured guide vane (2) has a numerical range of d ≤ s2 ≤ 10 d.

20. The trailing guide vane assembly according to claim 16, characterized in that: The contoured guide vane (2) has a second end away from the wind guide cap (1), and the second noise reduction structure is located within a range from the second end to 1 / 10r of the second end, where r is the radius of the rotating fan blade (6) corresponding to the rear guide vane assembly.

21. The trailing guide vane assembly according to claim 1, characterized in that: The rear guide vane assembly further comprises an air guide ring (5), the air guide cap (1) being arranged inside the air guide ring (5), the contoured guide vane (2) being arranged between the air guide cap (1) and the air guide ring (5), and an end of the contoured guide vane (2) away from the air guide cap (1) being arranged on the air guide ring (5).

22. An axial flow fan, characterized in that: A rear guide vane assembly comprising any one of claims 1 to 21.

23. The axial flow fan according to claim 22, characterized in that: The axial flow fan further comprises a housing and a rotating blade (6), wherein the rotating blade (6) is rotatably arranged in the housing, and the rear guide vane assembly is arranged in the housing, and the rear guide vane assembly is located on the outflow side of the rotating blade (6).

24. An air conditioner, characterized in that: The invention comprises the rear guide vane assembly according to any one of claims 1 to 21 or the axial flow fan according to claim 22 or 23.

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