Volute tongue assembly, centrifugal fan and air conditioner

Abstract

The utility model provides a volute tongue assembly, a centrifugal fan and an air conditioner. The volute tongue assembly comprises a volute tongue body and a volute tongue cover, wherein the volute tongue body is provided with a flow guide face through which airflow passes; the at least two profiling bulges are distributed on the flow guide surface in parallel; the shape of the profiling protrusion is a protrusion shape imitating the front edge of a fin limb of a seathead whale. According to the volute tongue assembly, the centrifugal fan and the air conditioner, due to the fact that the profiling protrusion in the shape of the protrusion on the front edge of the fin limb of the seat head whale is arranged, stalling of airflow on the front edge of the volute tongue can be delayed by enhancing momentum exchange between a boundary layer and a main flow, airflow distribution is optimized, vortex generation is changed, and therefore the vortex effect is improved. According to the volute tongue assembly, the volute tongue assembly can obtain good flowing performance, airflow separation at the volute tongue body is reduced, turbulent flow pulsating pressure generated by airflow impact is dispersed, airflow is guided to be in smooth transition, local backflow and secondary loss are reduced, pneumatic noise is restrained, and therefore the purposes of reducing noise of the centrifugal fan and improving working efficiency of the centrifugal fan are achieved.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal fan technology, and in particular to a volute assembly, a centrifugal fan, and an air conditioner. Background Technology

[0002] With the continuous improvement of people's living standards, fan coil unit terminal units are widely used in commercial and office buildings such as office buildings, hotels, and shopping malls. These places have relatively high requirements for environmental noise. Therefore, under the increasingly fierce market competition, it is imperative to improve the working efficiency of fan coil units while reducing their operating noise.

[0003] As a core component of fan coil units, the multi-blade centrifugal fan's efficiency and noise level directly affect the efficiency and noise of the fan coil unit. Existing multi-blade centrifugal fans have an unreasonable volute design, leading to high noise levels in the volute area. This noise primarily originates from two sources: firstly, the high-speed airflow from the impeller separates upon passing the volute, generating vortices. These vortices cause localized pressure fluctuations, resulting in aerodynamic noise. Furthermore, localized backflow occurs in the vortex region, reducing fan efficiency. Secondly, an improper gap (too large or too small) between the impeller and the volute can cause airflow turbulence or vibration, generating mechanical noise. Ultimately, this results in high noise levels and low efficiency for the centrifugal fan. Utility Model Content

[0004] To address the technical problem of high noise and low efficiency in centrifugal fans caused by unreasonable volute tongue structure design in existing technologies, a volute tongue assembly, centrifugal fan, and air conditioner are provided, which features contoured protrusions on the volute tongue body to suppress airflow separation and reduce aerodynamic noise as airflow passes through the volute tongue body, thereby reducing noise and improving efficiency.

[0005] A cochlear tongue assembly, comprising:

[0006] The volute tongue body has a guide surface through which airflow passes;

[0007] At least two contoured protrusions, all of which are arranged side-by-side on the guide surface;

[0008] The shape of the protrusion is modeled after the shape of the leading edge of the flipper of a humpback whale.

[0009] Along the airflow direction of the volute tongue body, the windward surface of the contoured protrusion has a first guide section, a second guide section, and a third guide section connected in sequence.

[0010] Along the airflow direction passing through the guide surface, the convex height of the first guide section gradually increases from zero, the convex height of the third guide section gradually decreases from greater than zero to zero, and the maximum convex height of the contoured convex part is located in the second guide section.

[0011] The profile of the second guide section includes a left peak and a right peak;

[0012] The fitting formula for the left peak is:

[0013]

[0014] The fitting formula for the right-hand peak is:

[0015]

[0016] The left peak and the right peak have a smooth transition;

[0017] Where: y is the ordinate of the fitted curve;

[0018] x is the x-axis of the fitted curve;

[0019] μ is the x-coordinate of the peak, representing the center position of the peak;

[0020] A represents the peak bulge amplitude, i.e., the y value when x = μ;

[0021] σ1 is the standard deviation of the Gaussian function on the left, which affects the width of the left peak;

[0022] σ² is the standard deviation of the Gaussian function on the right side, which affects the width of the peak on the right side;

[0023] exp is a computational relation representation, exp(x) = e x .

[0024] The formula for calculating the peak bulge amplitude A is as follows:

[0025] A = A0 + k * V(x);

[0026] Where A0 is the initial height of the contour protrusion, and its value ranges from 0.05H to 0.09H;

[0027] H is the height of the volute outlet where the volute tongue assembly is located;

[0028] k is a calculation constant, with a value range of [-0.20, -0.10];

[0029] V(x) is the airflow velocity in the width direction of the volute.

[0030] The formula for calculating the airflow velocity V(x) in the width direction of the volute is:

[0031] V(x) = z1x 3 +z2x 2 +z3x+Z;

[0032] Where x is the ratio of the distance from the wind speed point to the center of the volute tongue to the width of the volute tongue, and the value ranges from 0 to 0.5;

[0033] z1, z2, and z3 are all calculated coefficients;

[0034] Z is a calculation constant;

[0035] The portion between the center of the volute tongue body and one end of the volute tongue body is divided into 5 wind speed zones, and a wind speed point is set at the center of each wind speed zone.

[0036] The fitting formula for the profile of the first guide section is:

[0037] y=cx+C1, (2.80≤x<3.60);

[0038] Where y is the ordinate of the fitted curve;

[0039] x is the x-axis of the fitted curve;

[0040] c is the calculation coefficient, and c = -1.6216 ± 0.1325;

[0041] C1 is a calculation constant, and C1 = 4.6911 ± 0.1262.

[0042] The fitting formula for the profile of the third guide section is:

[0043] y = b1x 2 +b²x, (-1.54≤x<0);

[0044] Where y is the ordinate of the fitted curve;

[0045] x is the x-axis of the fitted curve;

[0046] b1 is the calculated coefficient, and b1 = 0.8022 ± 0.05811;

[0047] b2 is a calculation constant, and b2 = 4.0945 ± 0.1563.

[0048] The volute tongue assembly further includes a first noise reduction plate and a second noise reduction plate. A silencing cavity is formed in the middle of the volute tongue body. The silencing cavity forms an opening at the second flow guide section. The second noise reduction plate is located inside the silencing cavity. The first noise reduction plate is located at the opening, and the first noise reduction plate constitutes at least a portion of the second flow guide section.

[0049] The distance 'a' between the first noise reduction plate and the second noise reduction plate ranges from 0.013H to 0.025H, where H is the height of the volute outlet of the volute where the volute tongue assembly is located.

[0050] The shape of the first noise reduction plate is the same as that of the second noise reduction plate.

[0051] The first noise reduction plate is provided with a strip-shaped hole, the length direction of which is parallel to the width direction of the volute tongue body.

[0052] In the width direction of the volute tongue body, the center distance L1 between two adjacent strip holes ranges from 0.01L to 0.015L, where L is the width of the volute tongue body.

[0053] The width f of the strip hole ranges from 0.1 mm to 0.15 mm.

[0054] The thickness t1 of the first noise reduction plate ranges from 0.006H to 0.013H, where H is the height of the volute outlet of the volute where the volute tongue assembly is located.

[0055] The second noise reduction board is provided with multiple noise reduction holes, and all the noise reduction holes are distributed in an array.

[0056] In the width direction of the volute tongue body, the center distance L2 between two adjacent noise reduction holes ranges from 0.008L to 0.012L, where L is the width of the volute tongue body.

[0057] The diameter d of the noise reduction hole ranges from 0.1 mm to 0.2 mm.

[0058] The thickness t2 of the second noise reduction plate ranges from 0.006H to 0.013H, where H is the height of the volute outlet of the volute where the volute tongue assembly is located.

[0059] The distance e between the edge of the first noise reduction plate in the width direction and the edge of the contoured protrusion in the width s direction ranges from 0.02L to 0.1L, where L is the width of the volute tongue body.

[0060] The first end of the silencing cavity is located at the connection position between the first guide section and the second guide section, and the second end of the silencing cavity is located at the connection position between the second guide section and the third guide section.

[0061] The width s of the contoured protrusion ranges from 0.035L to 0.05L, where L is the width of the worm tongue body.

[0062] The volute tongue body has a leading edge pointing in the direction of airflow, and the contoured protrusion is disposed at the leading edge of the volute tongue.

[0063] A centrifugal fan includes the aforementioned volute assembly.

[0064] The volute tongue assembly, centrifugal fan, and air conditioner provided by this utility model, by setting a contoured protrusion in the shape of the leading edge protrusion of a humpback whale flipper, can enhance the momentum exchange between the boundary layer and the mainstream, delay the occurrence of airflow stall at the leading edge of the volute tongue, optimize airflow distribution, and change vortex generation. This allows the volute tongue assembly to obtain good flow performance, reduce airflow separation at the volute tongue body and disperse the turbulent pulsating pressure generated by airflow impact, lead to a smooth airflow transition, reduce local backflow and secondary losses, and suppress aerodynamic noise, thereby achieving the purpose of reducing centrifugal fan noise and improving centrifugal fan working efficiency. Attached Figure Description

[0065] Figure 1 A schematic diagram of the volute casing and volute tongue body of a centrifugal fan provided in an embodiment of this utility model;

[0066] Figure 2 This is a schematic diagram of the structure of the centrifugal fan and volute assembly provided in an embodiment of the present utility model;

[0067] Figure 3 This is a schematic diagram of the contour-following protrusion provided in an embodiment of the present utility model;

[0068] Figure 4 A schematic diagram of the profile of the contoured protrusion provided in an embodiment of this utility model;

[0069] Figure 5 Fitting curve diagram of the profile of the contoured protrusion provided for the embodiment of this utility model;

[0070] Figure 6 A side view of the contoured protrusion facing the airflow direction, provided for an embodiment of this utility model;

[0071] Figure 7 A cross-sectional view of the contoured protrusion provided in an embodiment of this utility model;

[0072] Figure 8 A schematic diagram of the structure of the first noise reduction plate with the contoured protrusion provided in this embodiment of the utility model;

[0073] Figure 9 A schematic diagram of the structure of the second noise reduction plate with contoured protrusion provided in an embodiment of this utility model;

[0074] Figure 10 This is a simulation diagram of airflow in a centrifugal fan in the existing technology;

[0075] Figure 11 A simulation diagram of airflow in a centrifugal fan equipped with the volute tongue assembly of this application;

[0076] In the picture:

[0077] 1. Volute tongue body; 11. Guide surface; 2. Contouring protrusion; 21. First guide section; 22. Second guide section; 23. Third guide section; 3. Volute shell; 31. Volute shell outlet; 12. Noise-reducing cavity; 41. First noise reduction plate; 42. Second noise reduction plate; 411. Strip hole; 421. Noise reduction hole. Detailed Implementation

[0078] To make the objectives, technical solutions, and advantages of this utility model clearer, 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 for explaining this utility model and are not intended to limit this utility model.

[0079] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0080] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate for the embodiments of the utility model described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0081] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," which indicate directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0082] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0083] As a core component of fan coil units, the multi-blade centrifugal fan's efficiency and noise level directly affect the efficiency and noise of the fan coil unit. Existing multi-blade centrifugal fans have an unreasonable volute design, leading to high noise levels in the volute area. This noise primarily originates from two sources: firstly, the high-speed airflow from the impeller separates upon passing the volute, generating vortices. These vortices cause localized pressure fluctuations, resulting in aerodynamic noise. Furthermore, localized backflow occurs in the vortex region, reducing fan efficiency. Secondly, an improper gap (too large or too small) between the impeller and the volute can cause airflow turbulence or vibration, generating mechanical noise. Ultimately, this results in high noise levels and low efficiency for the centrifugal fan.

[0084] Therefore, this application provides a method such as Figures 1 to 9 as well as Figure 11 The volute tongue assembly shown includes: a volute tongue body 1, the volute tongue body 1 having a guide surface 11 through which airflow passes; at least two contoured protrusions 2, all of which are arranged side-by-side on the guide surface 11; the shape of the contoured protrusions 2 is modeled after the shape of the leading edge protrusion of a humpback whale flipper. By setting the contoured protrusions 2 in the shape of the leading edge protrusion of a humpback whale flipper, the momentum exchange between the boundary layer and the mainstream can be enhanced, delaying the occurrence of airflow stall at the leading edge of the volute tongue, optimizing airflow distribution and changing vortex generation, so that the volute tongue assembly can obtain good flow performance, reduce airflow separation at the volute tongue body 1 and disperse the turbulent pulsating pressure generated by the airflow impact, leading to a smooth airflow transition, reducing local backflow and secondary losses, and suppressing aerodynamic noise, thereby achieving the purpose of reducing centrifugal fan noise and improving centrifugal fan efficiency.

[0085] As one implementation, along the airflow direction of the volute body 1, the windward surface of the contoured protrusion 2 has a first guide section 21, a second guide section 22, and a third guide section 23 connected in sequence. The second guide section 22 is located in the middle of the volute body 1 and faces the area of ​​concentrated pressure. Therefore, the second guide section 22 is used as the main contoured part. The shape of the protrusion at the leading edge of the humpback whale flipper is fully utilized to optimize the airflow to the volute body 1, so that the gas can obtain good flow performance, delay the occurrence of airflow stall at the leading edge of the volute, reduce the problem of start-up noise caused by airflow separation and local stall, and ensure the noise reduction effect of the contoured protrusion 2.

[0086] Along the airflow direction passing through the guide surface 11, the protrusion height of the first guide section 21 gradually increases from zero, and the protrusion height of the third guide section 23 gradually decreases from greater than zero to zero. The maximum protrusion height of the contoured protrusion 2 is located in the second guide section 22. That is, both the first guide section 21 and the third guide section 23 are used to make the second guide section 22 and the volute tongue body 1 smoothly transition, so that the airflow can flow smoothly when passing through the contoured protrusion 2, avoiding the problems of wind resistance and noise caused by the stepped cross section, and ensuring the noise reduction effect of the contoured protrusion 2.

[0087] The second guide section 22 is the main contouring part of the contoured protrusion 2. In order to make the contoured protrusion 2 as close as possible to the shape of the protruding structure at the leading edge of the humpback whale's flipper, the profile of the second guide section 22 is designed using a formula, specifically as follows:

[0088] The profile of the second guide section 22 includes a left peak and a right peak;

[0089] The fitting formula for the left peak is:

[0090]

[0091] The fitting formula for the right-hand peak is:

[0092]

[0093] The left peak and the right peak have a smooth transition;

[0094] Where: y is the ordinate of the fitted curve;

[0095] x is the x-axis of the fitted curve;

[0096] μ is the x-coordinate of the peak, representing the center position of the peak;

[0097] A represents the peak bulge amplitude, i.e., the y value when x = μ;

[0098] σ1 is the standard deviation of the Gaussian function on the left, which affects the width of the left peak;

[0099] σ² is the standard deviation of the Gaussian function on the right side, which affects the width of the peak on the right side;

[0100] exp is a computational relation representation, exp(x) = e x The second diversion section 22 is fitted using a Bigaussian single-peak curve.

[0101] The formula for calculating the peak bulge amplitude A is as follows:

[0102] A = A0 + k * V(x);

[0103] Where A0 is the initial height of the contour protrusion 2, and its value ranges from 0.05H to 0.09H;

[0104] H is the height of the volute outlet 31 of the volute 3 where the volute tongue assembly is located;

[0105] k is a calculation constant, with a value range of [-0.20, -0.10];

[0106] V(x) is the airflow velocity in the width direction of the volute.

[0107] The formula for calculating the airflow velocity V(x) in the width direction of the volute 3 is as follows:

[0108] V(x) = z1x³ + z2x² + z3x + Z;

[0109] Where x is the ratio of the distance from the wind speed point to the center of the volute tongue to the width of the volute tongue, and the value ranges from 0 to 0.5;

[0110] z1, z2, and z3 are all calculated coefficients;

[0111] Z is a calculation constant;

[0112] CFD flow field calculations of the airflow at outlet 31 of the volute show that, in the width direction of the volute tongue, with the centerline of the volute tongue as the axis, there is the same wind speed distribution pattern on both sides.

[0113] Optionally, when the width L of the volute tongue body 1 is 0.229m and the height H of the volute outlet 31 of the volute 3 where the volute tongue assembly is located is 0.074m, the value ranges of z1, z2, z3 and Z are respectively: z1 = 469.2 ± 1.231, z2 = -328.11 ± 0.511, z3 = 42.99 ± 0.253, and Z = 14.531 ± 0.625.

[0114] The portion between the center of the volute tongue body 1 and one end of the volute tongue body 1 is divided into 5 wind speed zones, and a wind speed point is set at the center of each wind speed zone.

[0115] The fitting formula for the profile of the first guide section 21 is:

[0116] y=cx+C1, (2.80≤x<3.60);

[0117] Where y is the ordinate of the fitted curve;

[0118] x is the x-axis of the fitted curve;

[0119] c is the calculation coefficient, and c = -1.6216 ± 0.1325;

[0120] C1 is a calculation constant, and C1 = 4.6911 ± 0.1262.

[0121] The fitting formula for the profile of the third guide section 23 is:

[0122] y = b1x 2 +b²x, (-1.54≤x<0);

[0123] Where y is the ordinate of the fitted curve;

[0124] x is the x-axis of the fitted curve;

[0125] b1 is the calculated coefficient, and b1 = 0.8022 ± 0.05811;

[0126] b2 is a calculation constant, and b2 = 4.0945 ± 0.1563.

[0127] To achieve individual processing of the contour protrusion 2, the profile of the contour protrusion 2 conforming to the volute tongue body 1 needs to be formulaically set. The profile of the contour protrusion 2 conforming to the volute tongue body 1 is defined as the leeward side profile, which is formed by a fourth-order polynomial fitting. The fitting formula is as follows:

[0128] y = d1x 4 +d2x 3 +d3x 2 +d4x+D, -1.54≤x≤3.60;

[0129] Where d1, d2, d3, and d4 are all calculation coefficients;

[0130] D is a calculation constant;

[0131] In this embodiment, d1 = 0.0148 ± 0.00568, d2 = -0.0977 ± 0.00135, d3 = -0.221 ± 0.0172, d4 = 1.588 ± 0.0632, and D = -1.9007 ± 0.0625.

[0132] By fitting and calculating the leeward profile of the first guide section 21, the second guide section 22, the third guide section 23 and the contoured protrusion 2 respectively, the cross-sectional profile of the contoured protrusion 2 can be obtained. Then, by stretching this cross-sectional profile according to the required width s of the contoured protrusion 2, a three-dimensional view of the contoured protrusion 2 can be obtained.

[0133] To further improve the noise reduction effect of the contoured protrusion 2, the volute tongue assembly also includes a first noise reduction plate 41 and a second noise reduction plate 42. A silencing cavity 12 is formed in the middle of the volute tongue body 1. The silencing cavity 12 has an opening at the second guide section 22. The second noise reduction plate 42 is located inside the silencing cavity 12. The first noise reduction plate 41 is located at the opening, and the first noise reduction plate 41 constitutes at least part of the second guide section 22. Using the channels on the first noise reduction plate 41 and the second noise reduction plate 42, part of the airflow flowing through the contoured protrusion 2 can pass through the first noise reduction plate 41 and the second noise reduction plate 42 and enter the silencing cavity 12. The channel of the first noise reduction plate 41 can cut the large-scale vortex of the airflow and suppress flow separation, and the channel of the second noise reduction plate 42 can further break the remaining mesoscale vortex into micro vortices, reducing the pressure pulsation intensity. Finally, the silencing cavity 12 selectively absorbs low-frequency noise based on the Helmholtz resonance effect. The synergistic effect of the first noise reduction plate 41, the second noise reduction plate 42 and the silencing cavity 12 can effectively reduce aerodynamic noise and improve the noise reduction effect of the contoured protrusion 2.

[0134] The distance 'a' between the first noise reduction plate 41 and the second noise reduction plate 42 ranges from 0.013H to 0.025H, where H is the height of the volute outlet 31 of the volute 3 where the volute tongue assembly is located. By limiting the range of distance 'a', reliable flow between the first noise reduction plate 41 and the second noise reduction plate 42 is ensured to guarantee the breaking effect of the eddy current by the second noise reduction plate 42, and the reliable separation of the space within the silencing cavity 12 by the second noise reduction plate 42 is also guaranteed, thereby ensuring the noise reduction effect of the silencing cavity 12.

[0135] Preferably, the second noise reduction plate 42 divides the silencing cavity 12 into a first silencing space and a second silencing space. The first silencing space is located between the first noise reduction plate 41 and the second noise reduction plate 42. At this time, the airflow first flows into the first silencing space through the first noise reduction plate 41, and then flows into the second silencing space through the second noise reduction plate 42. By limiting the spacing a, the volume of the first silencing space and the volume of the second silencing space can be adjusted, thereby adjusting the noise reduction effect of the first silencing space and the second silencing space.

[0136] Preferably, the shape of the first noise reduction plate 41 is the same as that of the second noise reduction plate 42, ensuring that the distance a between the first noise reduction plate 41 and the second noise reduction plate 42 is the same, thereby ensuring that the same airflow conditions can be obtained at any position of the second noise reduction plate 42, thereby ensuring the breaking effect of the second noise reduction plate 42 on the mesoscale eddies and improving the noise reduction effect of the contour protrusion 2.

[0137] The first noise reduction plate 41 is provided with a strip-shaped hole 411. The length direction of the strip-shaped hole 411 is parallel to the width direction of the volute tongue body 1. The strip-shaped hole 411 is a narrow slit shape. At this time, the strip-shaped hole 411 can cut the airflow through the slit, thereby cutting the large-scale vortex of the airflow to suppress flow separation, and preparing for the subsequent absorption of the medium-scale vortex and resonance in the silencing cavity 12 by the second noise reduction plate 42.

[0138] In the width direction of the volute tongue body 1, the center distance L1 between two adjacent strip holes 411 ranges from 0.01L to 0.015L, where L is the width of the volute tongue body 1. When the center distance L1 is too large, the number of strip holes 411 is small and their distribution is sparse. In this case, the cutting effect of the strip holes 411 on the airflow is reduced, and the airflow through the first noise reduction plate 41 will also be reduced, affecting the noise reduction effect of the second noise reduction plate 42 and the silencing cavity 12. When the center distance L1 is too small... When there are many slots 411, a large amount of airflow will flow into the silencing cavity 12 through the slots 411, making it impossible to use the resonance of the silencing cavity 12 for noise reduction. The large amount of airflow will also further affect the airflow breaking effect of the second noise reduction plate 42, resulting in poor noise reduction effect. Only when the center distance L1 is between 0.01L and 0.015L can the cutting effect of the slots 411 on the airflow be guaranteed, effectively suppressing flow separation, and providing an appropriate amount of airflow for the second noise reduction plate 42 to ensure the noise reduction effect.

[0139] The width f of the strip hole 411 ranges from 0.1mm to 0.15mm. By limiting the width f of the strip hole 411, the strip hole 411 is made as narrow as possible, which improves the cutting effect of the strip hole 411 on the airflow. However, if the width f of the strip hole 411 is too large, the cutting effect on the airflow will be reduced, affecting the noise reduction effect of the second noise reduction plate 42. When the width f of the strip hole 411 is too small, the airflow will not flow through the strip hole 411, and the strip hole 411 cannot play a cutting effect. Only when the width f is between 0.1mm and 0.15mm can the cutting effect on the airflow and the noise reduction effect of the second noise reduction plate 42 be guaranteed.

[0140] The thickness t1 of the first noise reduction plate 41 ranges from 0.006H to 0.013H, where H is the height of the volute outlet 31 of the volute 3 where the volute tongue assembly is located. The thickness of the first noise reduction plate 41 affects the channel length formed by the strip hole 411. When the thickness t1 is too large, an excessively long channel will be formed on the first noise reduction plate 41, affecting the cutting effect on the airflow. It will also increase the space occupied by the first noise reduction plate 41 on the silencing cavity 12, thus affecting the noise reduction effect of the silencing cavity 12. When the thickness t1 is too small, the structural reliability of the first noise reduction plate 41 will be poor, affecting the structural reliability of the contour protrusion 2. Only when the thickness t1 is between 0.006H and 0.013H can the structural reliability of the first noise reduction plate 41 and the cutting effect of the strip hole 411 on the airflow be guaranteed.

[0141] The second noise reduction plate 42 is provided with a plurality of noise reduction holes 421, all of which are arrayed. The noise reduction holes 421 are used to realize the flow of the first noise reduction zone and the second noise reduction zone. The airflow is broken by the noise reduction holes 421 during the flow of the airflow, thereby achieving the noise reduction effect.

[0142] In the width direction of the volute tongue body 1, the center distance L2 between two adjacent noise reduction holes 421 ranges from 0.008L to 0.012L, where L is the width of the volute tongue body 1. When the center distance L2 is too large, the number of noise reduction holes 421 is small and their distribution is sparse. In this case, the noise reduction holes 421 reduce the breaking effect on the airflow, and the airflow through the second noise reduction plate 42 will also decrease, affecting the noise reduction effect of the silencing cavity 12. When the center distance L2 is too small, the number of noise reduction holes is large, and a large amount of airflow will rush into the silencing cavity 12 through the noise reduction holes 421, making it impossible to use the resonance of the silencing cavity 12 for noise reduction, resulting in poor noise reduction effect. Only when the center distance L2 is between 0.008L and 0.012L can the breaking effect of the noise reduction holes 421 on the airflow be guaranteed, effectively suppressing flow separation and ensuring the noise reduction effect.

[0143] The diameter d of the noise reduction hole 421 ranges from 0.1 mm to 0.2 mm. If the diameter d of the noise reduction hole 421 is too large, the breaking effect on the airflow will be reduced, affecting the noise reduction effect of the second noise reduction plate 42. If the diameter d of the noise reduction hole 421 is too small, the airflow will not flow through the noise reduction hole 421, and the noise reduction hole 421 will not be able to cut the airflow. Only when the diameter d is between 0.1 mm and 0.2 mm can the breaking effect on the airflow and the noise reduction effect be guaranteed.

[0144] The thickness t2 of the second noise reduction plate 42 ranges from 0.006H to 0.013H, where H is the height of the volute outlet 31 of the volute 3 where the volute tongue assembly is located. The thickness of the second noise reduction plate 42 affects the channel length formed by the noise reduction hole 421. When the thickness t2 is too large, an excessively long channel will be formed on the second noise reduction plate 42, affecting the breaking effect of the airflow. At the same time, it will also increase the space occupied by the second noise reduction plate on the silencing cavity 12, thus affecting the noise reduction effect of the silencing cavity 12. When the thickness t2 is too small, the structural reliability of the second noise reduction plate 42 will be poor, affecting the structural reliability of the contour protrusion 2. Only when the thickness t2 is between 0.006H and 0.013H can the structural reliability of the second noise reduction plate 42 and the cutting effect of the strip hole 411 on the airflow be guaranteed.

[0145] The distance e between the edge of the first noise reduction plate 41 in the width direction and the edge of the contoured protrusion 2 in the width s direction ranges from 0.02L to 0.1L, where L is the width of the volute tongue body 1. That is, a portion of the solid structure is retained at both ends of the contoured protrusion 2 in the width direction, so that a cavity can be formed independently in the contoured protrusion 2. At this time, the contoured protrusion 2 does not need other structures to cooperate to achieve the noise reduction effect, ensuring the structural independence of the contoured protrusion 2. The distance e is set by using the retained solid structure to form the silencing cavity 12. The retained solid structure forms the sidewall of the silencing cavity 12. When the distance e is too large, the size of the first noise reduction plate 41, the second noise reduction plate 42 and the silencing cavity 12 are all small, and the noise reduction effect is poor. When the distance e is too small, the sidewall thickness of the silencing cavity 12 is small, and the structural reliability of the silencing cavity 12 and the contoured protrusion 2 cannot be guaranteed. Preferably, the distance e is 0.05L.

[0146] The first end of the silencing cavity 12 is located at the connection between the first guide section 21 and the second guide section 22, and the second end of the silencing cavity 12 is located at the connection between the second guide section 22 and the third guide section 23. The second guide section 22 is the area where airflow is concentrated on the contoured protrusion 2. At this time, the contoured protrusion 2 corresponding to the second guide section 22 can all form the silencing cavity 12, which can maximize the noise reduction effect of the silencing cavity 12. It can also increase the size of the first noise reduction plate 41 and the second noise reduction plate 42 to improve the noise reduction effect of the first noise reduction plate 41 and the second noise reduction plate 42, and ultimately improve the noise reduction effect of the contoured protrusion 2.

[0147] The width s of the contoured protrusion 2 ranges from 0.035L to 0.05L, where L is the width of the volute tongue body 1. When the width s of the contoured protrusion 2 is large, the number of contoured protrusions 2 decreases, and the contoured protrusion 2 may even replace the function of the volute tongue, not only failing to achieve the effect of airflow guidance and noise reduction but also causing an increase in noise. When the width s of the contoured protrusion 2 is small, the contoured protrusion 2 cannot reliably guide the airflow. Only when the width s of the contoured protrusion 2 is within the range of 0.035L to 0.05L can the contoured protrusion 2 reliably guide the airflow and reduce noise, ensuring the noise reduction effect of the volute tongue assembly.

[0148] The volute tongue body 1 has a leading edge pointing in the direction of airflow. The contoured protrusion 2 is disposed at the leading edge of the volute tongue. The contoured protrusion 2 in the pressure concentration area of ​​the leading edge of the volute tongue is provided with a second guide section 22, a sound-absorbing cavity 12, a first noise reduction plate 41, and a second noise reduction plate 42, which can effectively cut and break up the vortex in the airflow and improve the noise reduction effect of the volute tongue assembly.

[0149] A simulation comparison was performed between a centrifugal fan without protrusions in the prior art and a centrifugal fan with the contour protrusion 2 described in this application. Figure 10 and Figure 11 As shown, where Figure 10 This is a simulation diagram of airflow in a centrifugal fan in the existing technology; Figure 11 Simulation diagram of airflow in a centrifugal fan equipped with the volute assembly of this application:

[0150] from Figure 10 and Figure 11 The comparison shows that, at the same rotational speed, after the centrifugal fan with the contoured protrusion 2 of this application is equipped, the high-speed airflow from the impeller impacts the volute body 1, resulting in reduced airflow separation, improved stall performance, and smoother airflow transition guided by the contoured protrusion 2, thus improving the local backflow problem. Under the same operating conditions, the centrifugal fan with the contoured protrusion 2 of this application has a 1.5% higher airflow and a 0.5 dB lower noise level compared to the centrifugal fan without the protrusion. Therefore, the contoured protrusion 2 of this application can achieve better working performance and lower noise.

[0151] A centrifugal fan includes the aforementioned volute assembly.

[0152] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A volute tongue assembly, characterized in that: include: The volute tongue body (1) has a guide surface (11) through which airflow passes; At least two contoured protrusions (2) are arranged side by side on the guide surface (11); The shape of the protrusion (2) is similar to the shape of the protrusion at the front edge of the flipper of a humpback whale.

2. The volute tongue assembly according to claim 1, characterized in that: Along the airflow direction of the volute tongue body (1), the windward surface of the contoured protrusion (2) has a first guide section (21), a second guide section (22) and a third guide section (23) connected in sequence.

3. The volute tongue assembly according to claim 2, characterized in that: Along the airflow direction passing through the guide surface (11), the convex height of the first guide section (21) gradually increases from zero, the convex height of the third guide section (23) gradually decreases from greater than zero to zero, and the maximum convex height of the contoured convex convex 2 is located in the second guide section (22).

4. The volute tongue assembly according to claim 2, characterized in that: The profile of the second guide section (22) includes a left peak and a right peak; The fitting formula for the left peak is: The fitting formula for the right-hand peak is: The left peak and the right peak have a smooth transition; Where: y is the ordinate of the fitted curve; x is the x-axis of the fitted curve; μ is the x-coordinate of the peak, representing the center position of the peak; A represents the peak bulge amplitude, i.e., the y value when x = μ; σ1 is the standard deviation of the Gaussian function on the left, which affects the width of the left peak; σ² is the standard deviation of the Gaussian function on the right side, which affects the width of the peak on the right side; exp is a computational relation representation, exp(x) = e x .

5. The volute tongue assembly according to claim 4, characterized in that: The formula for calculating the peak bulge amplitude A is as follows: A = A0 + k * V(x); Where A0 is the initial height of the contour protrusion (2), and its value ranges from 0.05H to 0.09H; H is the height of the volute outlet (31) of the volute (3) where the volute tongue assembly is located; k is a calculation constant, with a value range of [-0.20, -0.10]; V(x) is the airflow velocity in the width direction of the volute (3).

6. The volute tongue assembly according to claim 5, characterized in that: The formula for calculating the airflow velocity V(x) in the width direction of the volute (3) is as follows: V(x)=z1x 3 +z2x 2 +z3x+Z; Where x is the ratio of the distance from the wind speed point to the center of the volute tongue to the width of the volute tongue, and the value ranges from 0 to 0.5; z1, z2, and z3 are all calculated coefficients; Z is a calculation constant; The portion between the center of the volute tongue body (1) and one end of the volute tongue body (1) is divided into 5 wind speed zones, and a wind speed point is set at the center of each wind speed zone.

7. The volute tongue assembly according to claim 2, characterized in that: The fitting formula for the profile of the first guide section (21) is: y=cx+C1, (2.80≤x<3.60); Where y is the ordinate of the fitted curve; x is the x-axis of the fitted curve; c is the calculation coefficient, and c = -1.6216 ± 0.1325; C1 is a calculation constant, and C1 = 4.6911 ± 0.1262.

8. The volute tongue assembly according to claim 2, characterized in that: The fitting formula for the profile of the third guide section (23) is: y=b1x 2 +b2x,(-1.54≤x<0); Where y is the ordinate of the fitted curve; x is the x-axis of the fitted curve; b1 is the calculated coefficient, and b1 = 0.8022 ± 0.05811; b2 is a calculation constant, and b2 = 4.0945 ± 0.1563.

9. The volute tongue assembly according to claim 2, characterized in that: The volute tongue assembly further includes a first noise reduction plate (41) and a second noise reduction plate (42). A silencing cavity (12) is formed in the middle of the volute tongue body (1). The silencing cavity (12) forms an opening at the second flow guide section (22). The second noise reduction plate (42) is located inside the silencing cavity (12). The first noise reduction plate (41) is located at the opening, and the first noise reduction plate (41) constitutes at least a portion of the second flow guide section (22).

10. The volute tongue assembly according to claim 9, characterized in that: The distance a between the first noise reduction plate (41) and the second noise reduction plate (42) ranges from 0.013H to 0.025H, where H is the height of the volute outlet (31) of the volute (3) where the volute tongue assembly is located.

11. The volute tongue assembly according to claim 9, characterized in that: The shape of the first noise reduction plate (41) is the same as that of the second noise reduction plate (42).

12. The volute tongue assembly according to claim 9, characterized in that: The first noise reduction plate (41) is provided with a strip hole (411), the length direction of which is parallel to the width direction of the volute tongue body (1).

13. The volute tongue assembly according to claim 12, characterized in that: In the width direction of the volute tongue body (1), the center distance L1 between two adjacent strip holes (411) ranges from 0.01L to 0.015L, where L is the width of the volute tongue body (1).

14. The volute tongue assembly according to claim 12, characterized in that: The width f of the strip hole (411) ranges from 0.1 mm to 0.15 mm.

15. The volute tongue assembly according to claim 9, characterized in that: The thickness t1 of the first noise reduction plate (41) ranges from 0.006H to 0.013H, where H is the height of the volute outlet (31) of the volute (3) where the volute tongue assembly is located.

16. The volute tongue assembly according to claim 9, characterized in that: The second noise reduction plate (42) is provided with a plurality of noise reduction holes (421), and all the noise reduction holes (421) are arranged in an array.

17. The volute tongue assembly according to claim 16, characterized in that: In the width direction of the volute tongue body (1), the center distance L2 between two adjacent noise reduction holes (421) ranges from 0.008L to 0.012L, where L is the width of the volute tongue body (1).

18. The volute tongue assembly according to claim 16, characterized in that: The diameter d of the noise reduction hole (421) ranges from 0.1 mm to 0.2 mm.

19. The volute tongue assembly according to claim 9, characterized in that: The thickness t2 of the second noise reduction plate (42) ranges from 0.006H to 0.013H, where H is the height of the volute outlet (31) of the volute (3) where the volute tongue assembly is located.

20. The volute tongue assembly according to claim 9, characterized in that: The distance e between the edge of the first noise reduction plate (41) in the width direction and the edge of the contour protrusion (2) in the width s direction ranges from 0.02L to 0.1L, where L is the width of the worm tongue body (1).

21. The volute tongue assembly according to claim 9, characterized in that: The first end of the silencing cavity (12) is located at the connection between the first guide section (21) and the second guide section (22), and the second end of the silencing cavity (12) is located at the connection between the second guide section (22) and the third guide section (23).

22. The volute tongue assembly according to claim 1, characterized in that: The width s of the contour protrusion (2) ranges from 0.035L to 0.05L, where L is the width of the snail tongue body (1).

23. The volute tongue assembly according to claim 1, characterized in that: The worm tongue body (1) has a worm tongue leading edge pointing in the direction of airflow, and the contour protrusion (2) is provided at the worm tongue leading edge.

24. A centrifugal fan, characterized in that: The worm tongue assembly included in any one of claims 1 to 23.

25. An air conditioner, characterized in that: Includes the volute assembly according to any one of claims 1 to 23 or the centrifugal fan according to claim 24.

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