Volute tongue assembly, centrifugal fan and air conditioner

Abstract

The invention 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 provided by the invention, by arranging the profiling bulge in the shape of the bulge at the front edge of the fin limb of the seat head whale, the occurrence of stall of airflow at 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 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] The present invention relates to the technical field of centrifugal fans, in particular to a volute tongue component, a centrifugal fan and an air conditioner. Background Art

[0002] With the continuous improvement of people's living standards, fan coil 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 the operating noise of the fan coil.

[0003] As the core component of the fan coil unit, the multi-blade centrifugal fan's working efficiency and noise level directly affect the efficiency and noise of the fan coil. The volute tongue design of the multi-blade centrifugal fan in the existing technology is unreasonable, which makes it easy to generate high noise in the volute tongue area. The noise mainly comes from two aspects. On the one hand, it may be that the high-speed airflow from the impeller separates the airflow when passing through the volute tongue, generating vortices. These vortices will cause local pressure fluctuations, resulting in aerodynamic noise. At the same time, local backflow will also occur in the area where the vortex occurs, resulting in a decrease in the fan efficiency. On the other hand, the improper gap between the impeller and the volute tongue (too large or too small) may cause airflow turbulence or vibration, thereby generating mechanical noise, which ultimately causes the centrifugal fan to have high noise and low working efficiency. Summary of the Invention

[0004] In order to solve the technical problems of high noise and low working efficiency of centrifugal fans caused by unreasonable design of the volute tongue structure in the prior art, a volute tongue assembly, a centrifugal fan and an air conditioner are provided in which a contoured protrusion is provided on the volute tongue body to suppress airflow separation and reduce the aerodynamic noise of the airflow passing through the volute tongue body, so as to achieve the purpose of reducing noise and improving working efficiency.

[0005] A volute tongue assembly, comprising:

[0006] A volute tongue body, wherein the volute tongue body has a flow guide surface for airflow to pass through;

[0007] at least two profiling protrusions, all of which are arranged side by side on the guide surface;

[0008] The shape of the protrusion imitates the protrusion of the front 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 which are connected in sequence.

[0010] Along the airflow direction passing through the guide surface, the protrusion height of the first guide section gradually increases from zero, the protrusion height of the third guide section gradually decreases from greater than zero to zero, and the maximum protrusion height part of the contoured protrusion 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 of the left peak is:

[0013] 0≤x<1.3779;

[0014] The fitting formula of the right peak is:

[0015] 1.44≤x<2.95;

[0016] There is a smooth transition between the left peak and the right peak;

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

[0018] x is the horizontal coordinate of the fitting curve;

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

[0020] A is the convex amplitude of the peak, that is, 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 peak on the left;

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

[0023] exp is a method of expressing a calculation relationship, exp(x) = e x .

[0024] The calculation formula of the peak convex amplitude A is:

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

[0026] Among them, A0 is the starting height of the protrusion, and its value range is 0.05H to 0.09H;

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

[0028] k is a calculation constant, and its value range is [-0.20, -0.10];

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

[0030] The calculation formula of 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 snail tongue to the width of the snail tongue, and its value range is 0 to 0.5;

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

[0034] Z is the calculation constant;

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

[0036] The fitting formula of 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 fitting curve;

[0039] x is the horizontal coordinate of the fitting 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 of 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 fitting curve;

[0045] x is the horizontal coordinate of the fitting curve;

[0046] b1 is a calculation coefficient, and b1=0.8022±0.05811;

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

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

[0049] The numerical range of the distance a between the first noise reduction plate and the second noise reduction plate is 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 hole, and the length direction of the strip hole is parallel to the width direction of the snail tongue body.

[0052] In the width direction of the volute tongue body, the center distance L1 between two adjacent strip-shaped 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-shaped 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 plate is provided with a plurality of 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 snail tongue body.

[0060] The first end of the muffler cavity is located at the connection position of the first guide section and the second guide section, and the second end of the muffler cavity is located at the connection position of 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 volute tongue body.

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

[0063] A centrifugal fan comprises the above-mentioned volute tongue assembly.

[0064] The volute tongue assembly, centrifugal fan, and air conditioner provided by the present invention can enhance the momentum exchange between the boundary layer and the mainstream by setting a contoured protrusion in the shape of the protrusion on the leading edge of the humpback whale flipper, delay the occurrence of airflow stall at the leading edge of the volute tongue, optimize the airflow distribution and change the vortex generation, so that the volute tongue assembly can obtain good flow performance, reduce the airflow separation at the volute tongue body and the turbulent pulsation pressure generated by the impact of the dispersed airflow, lead to a smooth transition of the airflow, reduce local backflow and secondary losses, and suppress aerodynamic noise, thereby achieving the purpose of reducing the noise of the centrifugal fan and improving the working efficiency of the centrifugal fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A schematic structural diagram of a volute and a volute tongue body of a centrifugal fan provided in an embodiment of the present invention;

[0066] Figure 2 A schematic structural diagram of a centrifugal fan and a volute tongue assembly provided in an embodiment of the present invention;

[0067] Figure 3 A schematic structural diagram of a contoured protrusion provided in an embodiment of the present invention;

[0068] Figure 4 A schematic diagram of a profiled protrusion provided in an embodiment of the present invention;

[0069] Figure 5 A fitting curve diagram of the profile line of the protrusion provided in an embodiment of the present invention;

[0070] Figure 6 A side view of the contoured protrusion provided in an embodiment of the present invention facing the airflow direction;

[0071] Figure 7 A cross-sectional view of a contoured protrusion provided in an embodiment of the present invention;

[0072] Figure 8 A schematic structural diagram of a first noise reduction plate with a contoured protrusion provided in an embodiment of the present invention;

[0073] Figure 9 A schematic structural diagram of a second noise reduction plate with a contoured protrusion provided in an embodiment of the present invention;

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

[0075] Figure 11 This is a simulation diagram of the airflow of a centrifugal fan equipped with the volute tongue assembly of the present application;

[0076] In the picture:

[0077] 1. Volute tongue body; 11. Guide surface; 2. Contoured protrusion; 21. First guide section; 22. Second guide section; 23. Third guide section; 3. Volute; 31. Volute outlet; 12. Silence chamber; 41. First noise reduction plate; 42. Second noise reduction plate; 411. Strip hole; 421. Noise reduction hole. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is 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 invention and are not intended to limit the present invention.

[0079] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0080] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate the embodiments of the present invention described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or apparatuses.

[0081] It should be noted that, in the description of the present invention, terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These terms are used solely for ease of description and are not intended to indicate or imply that the devices or components described must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. 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 the present invention, unless otherwise expressly specified or limited, the terms "installed," "disposed," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0083] As the core component of the fan coil unit, the multi-blade centrifugal fan's working efficiency and noise level directly affect the efficiency and noise of the fan coil. The volute tongue design of the multi-blade centrifugal fan in the existing technology is unreasonable, which makes it easy to generate high noise in the volute tongue area. The noise mainly comes from two aspects. On the one hand, it may be that the high-speed airflow from the impeller separates the airflow when passing through the volute tongue, generating vortices. These vortices will cause local pressure fluctuations, resulting in aerodynamic noise. At the same time, local backflow will also occur in the area where the vortex occurs, resulting in a decrease in the fan efficiency. On the other hand, the improper gap between the impeller and the volute tongue (too large or too small) may cause airflow turbulence or vibration, thereby generating mechanical noise, which ultimately causes the centrifugal fan to have high noise and low working efficiency.

[0084] To this end, this application provides a Figures 1 to 9 as well as Figure 11 The illustrated volute tongue assembly comprises a volute tongue body 1 having a guide surface 11 through which air flows; at least two contoured protrusions 2, all of which are arranged in parallel on the guide surface 11; the contoured protrusions 2 are shaped like the protrusions on the leading edge of a humpback whale's flipper. By providing contoured protrusions 2 shaped like the protrusions on the leading edge of a humpback whale's flipper, momentum exchange between the boundary layer and the mainstream is enhanced, delaying the onset of airflow stall at the leading edge of the volute tongue, optimizing airflow distribution and altering vortex generation. This allows the volute tongue assembly to achieve excellent flow performance, reduce airflow separation at the volute tongue body 1, and disperse the turbulent pulsating pressure generated by airflow impact, leading to a smooth transition of airflow, reducing local backflow and secondary losses, and suppressing aerodynamic noise, thereby reducing centrifugal fan noise and improving its operating efficiency.

[0085] As an embodiment, along the airflow direction of the snail 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, wherein the second guide section 22 is located in the middle position of the snail tongue body 1, and faces the area of concentrated pressure. Therefore, the second guide section 22 is used as the main contoured part, and the shape of the convex leading edge of the humpback whale flipper is fully utilized to optimize the airflow flowing to the snail tongue body 1, so that the gas can obtain good flow performance, delay the occurrence of airflow stall at the leading edge of the snail tongue, reduce the problem of startup noise caused by airflow separation and local stall, and ensure the noise reduction effect of the contoured protrusion 2.

[0086] Along the direction of airflow passing through the guide surface 11, the raised height of the first guide segment 21 gradually increases from zero, while the raised height of the third guide segment 23 gradually decreases from greater than zero to zero. The maximum raised height of the contoured protrusion 2 is located in the second guide segment 22. In other words, both the first guide segment 21 and the third guide segment 23 are used to achieve a smooth transition between the second guide segment 22 and the volute tongue body 1, thereby allowing airflow to flow smoothly 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 profiling part of the profiling protrusion 2. In order to make the profiling protrusion 2 as close as possible to the shape of the protruding structure of the leading edge of the humpback whale flipper, the profile of the second guide section 22 is designed in a formulaic manner, specifically:

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

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

[0090] 0≤x<1.3779;

[0091] The fitting formula of the right peak is:

[0092] 1.44≤x<2.95;

[0093] There is a smooth transition between the left peak and the right peak;

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

[0095] x is the horizontal coordinate of the fitting curve;

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

[0097] A is the convex amplitude of the peak, that is, 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 peak on the left;

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

[0100] exp is a method of expressing a calculation relationship, exp(x) = e x The second diversion section 22 is fitted using a Bigaussian single-peak curve.

[0101] The calculation formula of the peak convex amplitude A is:

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

[0103] Wherein, A0 is the starting height of the protrusion 2, and its value range is 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, and its value range is [-0.20, -0.10];

[0106] V(x) is the air flow velocity in the width direction of the volute 3.

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

[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 snail tongue to the width of the snail tongue, and its value range is 0 to 0.5;

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

[0111] Z is the calculation constant;

[0112] Through CFD flow field calculation of the airflow at the volute outlet 31, it can be seen that in the width direction of the volute tongue, with the center line of the volute tongue as the axis, the two sides have the same wind speed distribution pattern.

[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: z1 = 469.2±1.231, z2 = -328.11±0.511, z3 = 42.99±0.253, Z = 14.531±0.625.

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

[0115] The fitting formula of 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 fitting curve;

[0118] x is the horizontal coordinate of the fitting 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 of 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 fitting curve;

[0124] x is the horizontal coordinate of the fitting curve;

[0125] b1 is a calculation coefficient, and b1=0.8022±0.05811;

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

[0127] In order to realize the separate processing of the profiling protrusion 2, it is necessary to formulate the profile line of the profiling protrusion 2 fitting the volute tongue body 1. The profile line of the profiling protrusion 2 fitting the volute tongue body 1 is defined as the leeward profile line, which is formed by fourth-order polynomial fitting. The fitting formula is:

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

[0129] Among them, d1, d2, d3, and d4 are calculation coefficients;

[0130] D is the 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 profiles 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, the cross-sectional profile is stretched according to the required width s of the contoured protrusion 2 to obtain a three-dimensional image of the contoured protrusion 2.

[0133] In order to further improve the noise reduction effect of the contoured protrusion 2, the snail tongue assembly also includes a first noise reduction plate 41 and a second noise reduction plate 42. A silencer cavity 12 is formed in the middle of the snail tongue body 1. The silencer cavity 12 forms an opening at the second guide section 22. The second noise reduction plate 42 is located in the silencer 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. By utilizing 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 silencer cavity 12. The channel of the first noise reduction plate 41 can cut the large-scale vortex clusters of the airflow and suppress flow separation, and the channel of the second noise reduction plate 42 can further break the remaining mesoscale vortices into micro-vortices, reducing the pressure pulsation intensity. Finally, the silencer cavity 12 is used to selectively absorb 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 silencer cavity 12 can effectively reduce aerodynamic noise and improve the noise reduction effect of the contoured protrusion 2.

[0134] The spacing a between the first noise reduction plate 41 and the second noise reduction plate 42 ranges from 0.013H to 0.025H, where H represents the height of the volute outlet 31 of the volute 3 in which the volute tongue assembly is located. By limiting the range of spacing a, reliable flow between the first noise reduction plate 41 and the second noise reduction plate 42 is ensured, thereby ensuring the second noise reduction plate 42's vortex-breaking effect. This also ensures that the second noise reduction plate 42 reliably separates the space within the muffler chamber 12, thereby maintaining the noise reduction effect of the muffler chamber 12.

[0135] Preferably, the second noise reduction plate 42 separates the silencer cavity 12 into a first silencer space and a second silencer space. The first silencer 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 silencer space through the first noise reduction plate 41, and then flows into the second silencer space through the second noise reduction plate 42. At this time, by limiting the distance a, the volume of the first silencer space and the second silencer space can be adjusted, thereby adjusting the noise reduction effect of the first silencer space and the second silencer space.

[0136] Preferably, the shape of the first noise reduction plate 41 is the same as the shape of the second noise reduction plate 42, ensuring that the spacing 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 second noise reduction plate 42 has a breaking effect on the mesoscale vortex, thereby improving the noise reduction effect of the contoured protrusion 2.

[0137] A strip hole 411 is provided on the first noise reduction plate 41. The length direction of the strip hole 411 is parallel to the width direction of the volute tongue body 1. The strip hole 411 is in the shape of a long and narrow slit. At this time, the strip hole 411 can be used to achieve slit cutting of the airflow, thereby cutting large-scale vortices of the airflow to suppress flow separation, and prepare for the subsequent second noise reduction plate 42 to absorb the mesoscale vortices and the resonance in the silencer cavity 12.

[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 the distribution is sparse. At this time, the cutting effect of the strip holes 411 on the airflow is reduced, and the airflow passing through the first noise reduction plate 41 is also reduced, which affects the noise reduction effect of the second noise reduction plate 42 and the silencer cavity 12. When the center distance L1 is too small, the airflow is reduced. When the number of the strip holes 411 is large, a large amount of airflow will flow into the silencer chamber 12 through the strip holes 411, and the resonance of the silencer chamber 12 cannot be used for silencing. A large amount of airflow will further affect the second noise reduction plate 42's effect of breaking up the airflow, resulting in poor noise reduction effect. Only when the center distance L1 is between 0.01L and 0.015L can the strip holes 411 have a cutting effect on the airflow, effectively suppressing flow separation, and providing the second noise reduction plate 42 with an appropriate amount of airflow to ensure 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, thereby improving the cutting effect of the strip hole 411 on the airflow. However, when 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 achieve the 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 represents the height of the volute outlet 31 of the volute 3 in which the volute tongue assembly is located. The thickness of the first noise reduction plate 41 affects the length of the channel formed by the strip-shaped holes 411. When the thickness t1 is too large, an excessively long channel will be formed on the first noise reduction plate 41, affecting the airflow cutting effect. At the same time, the space occupied by the first noise reduction plate 41 in the silencer cavity 12 will also increase, affecting the noise reduction effect of the silencer 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 contoured 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 airflow cutting effect of the strip-shaped holes 411 be guaranteed.

[0141] The second noise reduction plate 42 is provided with a plurality of noise reduction holes 421, and all the noise reduction holes 421 are distributed in an array. The noise reduction holes 421 are used to realize the flow between the first silencer interval and the second silencer interval. The airflow will be broken by the noise reduction holes 421 in the process of flowing through the noise reduction holes 421, thereby achieving a 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 has a value range of 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 the distribution is sparse. At this time, the effect of the noise reduction holes 421 on the airflow fragmentation is reduced, and the airflow passing through the second noise reduction plate 42 will also be reduced, affecting the noise reduction effect of the silencer cavity 12. When the center distance L2 is too small, the amount of noise reduction is large, and a large amount of airflow will flow into the silencer cavity 12 through the noise reduction holes 421, making it impossible to utilize the resonance of the silencer 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 noise reduction holes 421 have a fragmentation effect on the airflow, effectively suppressing flow separation and ensuring noise reduction effect.

[0143] The diameter d of the noise reduction holes 421 ranges from 0.1 mm to 0.2 mm. If the diameter d of the noise reduction holes 421 is too large, the airflow fragmentation effect will be reduced, affecting the noise reduction effect of the second noise reduction plate 42. If the diameter d of the noise reduction holes 421 is too small, the airflow will not flow through the noise reduction holes 421, and the noise reduction holes 421 will not have a cutting effect. Only when the diameter d is between 0.1 mm and 0.2 mm can the airflow fragmentation effect and 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 represents the height of the volute outlet 31 of the volute 3 in which the volute tongue assembly is located. The thickness of the second noise reduction plate 42 affects the length of the channel formed by the noise reduction holes 421. When the thickness t2 is too large, an excessively long channel will be formed on the second noise reduction plate 42, affecting the airflow fragmentation effect. At the same time, the space occupied by the second noise reduction plate in the silencer cavity 12 will also be increased, affecting the noise reduction effect of the silencer 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 contoured 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 airflow cutting effect of the strip holes 411 be guaranteed.

[0145] The distance e between the widthwise edge of the first noise reduction plate 41 and the widthwise edge of the contoured protrusion 2 is in the range of 0.02L to 0.1L, where L is the width of the tongue body 1. Specifically, a portion of the solid structure is retained at both ends of the contoured protrusion 2 in the widthwise direction, thereby independently forming a cavity within the contoured protrusion 2. In this case, the contoured protrusion 2 does not require the cooperation of other structures to achieve the noise reduction effect, ensuring the structural independence of the contoured protrusion 2. The distance e is set so that the retained solid structure encloses the silencer cavity 12, which forms the sidewalls of the silencer cavity 12. If the distance e is too large, the first noise reduction plate 41, the second noise reduction plate 42, and the silencer cavity 12 are all small, resulting in poor noise reduction. If the distance e is too small, the sidewall thickness of the silencer cavity 12 is too small, and the structural reliability of the silencer cavity 12 and the contoured protrusion 2 cannot be guaranteed. Preferably, the distance e is 0.05L.

[0146] The first end of the muffler 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 muffler 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 concentrates on the contoured protrusion 2. At this time, the portion of the contoured protrusion 2 corresponding to the second guide section 22 can form the muffler cavity 12, which can maximize the noise reduction effect of the muffler 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, ultimately improving the noise reduction effect of the contoured protrusion 2.

[0147] The width s of the protrusion 2 ranges from 0.035L to 0.05L, where L is the width of the tongue body 1. When the width s of the protrusion 2 is large, the number of protrusions 2 required decreases, and the protrusions 2 may even replace the tongue's function. This not only fails to guide airflow and reduce noise, but may actually increase noise. When the width s of the protrusion 2 is small, the protrusion 2 cannot reliably guide airflow. Only when the width s of the protrusion 2 is within the range of 0.035L to 0.05L can the protrusion 2 reliably guide airflow and reduce noise, ensuring the noise reduction effect of the tongue assembly.

[0148] The volute tongue body 1 has a volute tongue leading edge pointing to the direction of the airflow, and the profiling protrusion 2 is arranged at the leading edge of the volute tongue, wherein the profiling protrusion 2 corresponding to the pressure concentration area of the leading edge of the volute tongue is provided with a second guide section 22 and a silencer cavity 12, a first noise reduction plate 41 and a second noise reduction plate 42, which fully cut and crush the vortex in the airflow and improve the noise reduction effect of the volute tongue assembly.

[0149] A centrifugal fan without protrusions in the prior art and a centrifugal fan with the contoured protrusions 2 of the present application are simulated and compared. Figure 10 and Figure 11 As shown, Figure 10 This is a simulation diagram of the airflow of a centrifugal fan in the prior art; Figure 11 This is a simulation diagram of the airflow of a centrifugal fan equipped with the volute tongue assembly of the present application:

[0150] from Figure 10 and Figure 11From the comparison, it can be seen that at the same speed, after the centrifugal fan equipped with the profiled protrusion 2 of the present application is provided, the high-speed airflow from the impeller, after impacting the volute tongue body 1, has reduced airflow separation, improved stall performance, and the airflow can smoothly transition through the guidance of the profiled protrusion 2, and the local backflow problem is improved. Under the same working conditions, the air volume of the centrifugal fan equipped with the profiled protrusion 2 of the present application is increased by 1.5% compared to the centrifugal fan without the protrusion, and the noise is reduced by 0.5dB. Therefore, the profiled protrusion 2 of the present application can achieve better working results and lower noise effects.

[0151] A centrifugal fan comprises the above-mentioned volute tongue assembly.

[0152] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A volute tongue assembly, characterized in that: include: A volute tongue body (1), wherein the volute tongue body (1) has a flow guide surface (11) through which air flows; at least two profiling protrusions (2), all of the profiling protrusions (2) being distributed side by side on the guide surface (11); The shape of the protrusion (2) is similar to the protrusion on the front edge of a humpback whale flipper.

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 flow guide section (21), a second flow guide section (22) and a third flow guide section (23) which are connected in sequence.

3. The volute tongue assembly according to claim 2, characterized in that: Along the direction of the airflow flowing through the guide surface (11), the protrusion height of the first guide section (21) gradually increases from zero, the protrusion height of the third guide section (23) gradually decreases from greater than zero to zero, and the maximum protrusion height portion of the contoured protrusion (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 of the left peak is: The fitting formula of the right peak is: There is a smooth transition between the left peak and the right peak; Where: y is the ordinate of the fitting curve; x is the horizontal coordinate of the fitting curve; μ is the x-coordinate of the peak top, indicating the center position of the peak; A is the convex amplitude of the peak, that is, the y value when x = μ; σ1 is the standard deviation of the Gaussian function on the left, which affects the width of the peak on the left; σ2 is the standard deviation of the Gaussian function on the right, which affects the width of the peak on the right; exp is a method of expressing a calculation relationship, exp(x) = e x .

5. The volute tongue assembly according to claim 4, characterized in that: The calculation formula of the peak convex amplitude A is: A=A0+k*V(x); Wherein, A0 is the starting height of the protrusion (2), and its value range is 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, and its value range is [-0.20, -0.10]; V(x) is the air flow velocity in the width direction of the volute (3).

6. The volute tongue assembly according to claim 5, characterized in that: The calculation formula of the airflow velocity V(x) in the width direction of the volute (3) is: 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 snail tongue to the width of the snail tongue, and its value range is 0 to 0.5; z1, z2, and z3 are all calculation coefficients; Z is the calculation constant; The portion between the center of the snail tongue body (1) and one end of the snail tongue body (1) is divided into five wind speed zones, and the 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 of the profile of the first guide section (21) is: y=cx+C1, (2.80≤x<3.60); Where y is the ordinate of the fitting curve; x is the horizontal coordinate of the fitting 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 of the profile of the third guide section (23) is: y=b1x 2 +b2x,(-1.54≤x<0); Where y is the ordinate of the fitting curve; x is the horizontal coordinate of the fitting curve; b1 is a calculation 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 comprises a first noise reduction plate (41) and a second noise reduction plate (42); a silencer cavity (12) is formed in the middle of the volute tongue body (1); the silencer cavity (12) forms an opening at the second guide section (22); the second noise reduction plate (42) is located in the silencer 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 guide section (22).

10. The volute tongue assembly according to claim 9, characterized in that: The numerical range of the distance a between the first noise reduction plate (41) and the second noise reduction plate (42) is 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, wherein: The shape of the first noise reduction plate (41) is the same as the shape of the second noise reduction plate (42).

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

13. The volute tongue assembly according to claim 12, wherein: In the width direction of the volute tongue body (1), the center distance L1 between two adjacent strip-shaped 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, wherein: The width f of the strip-shaped hole (411) ranges from 0.1 mm to 0.15 mm.

15. The volute tongue assembly according to claim 9, wherein: The thickness t1 of the first noise reduction plate (41) has a value range of 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, wherein: The second noise reduction plate (42) is provided with a plurality of noise reduction holes (421), and all the noise reduction holes (421) are distributed in an array.

17. The volute tongue assembly according to claim 16, wherein: 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, wherein: 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, wherein: 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, wherein: 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 has a value ranging from 0.02L to 0.1L, where L is the width of the volute tongue body (1).

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

22. The volute tongue assembly according to claim 1, wherein: 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).

23. The volute tongue assembly according to claim 1, wherein: The volute tongue body (1) has a volute tongue leading edge pointing in the direction of the airflow, and the contoured protrusion (2) is arranged at the volute tongue leading edge.

24. A centrifugal fan, characterized in that: A volute tongue assembly comprising the volute tongue assembly according to any one of claims 1 to 23.

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

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