Centrifugal impeller, centrifugal fan and apparatus using centrifugal fan

Abstract

The application belongs to the technical field of fans, and discloses a centrifugal impeller, a centrifugal fan and equipment using the centrifugal fan. The blades of the centrifugal impeller are provided with a non-equal-thickness blade structure. The thickness of the blades gradually increases from inside to outside along the radial direction of the connecting disc. The width of the airflow channel gradually increases and then gradually decreases from inside to outside along the radial direction of the connecting disc. The width near the air outlet end of the airflow channel slowly decreases. The airflow channel between two adjacent blades forms an effective airflow buffer area, so that the airflow can flow better in the airflow channel between the two adjacent blades, the vortex on the pressure surface is reduced, the noise is reduced, the work capacity of the centrifugal impeller at high speed is increased, and the static pressure capacity of the centrifugal impeller is higher.

Description

Technical Field

[0001] This invention relates to the field of fan technology, and more particularly to a centrifugal impeller, a centrifugal fan, and equipment using the centrifugal fan. Background Technology

[0002] For equipment that uses centrifugal fans, such as gas water heaters, the main function of the centrifugal fan is to extract the high-temperature flue gas from the combustion chamber.

[0003] Traditional centrifugal impellers are generally designed with uniform thickness, forming an airflow channel between two adjacent blades. When the centrifugal impeller rotates and the airflow passes through this airflow channel, part of the airflow flows out along the suction surface of the blades that form the airflow channel, and the other part flows out along the pressure surface of the airflow channel. When the airflow flows along the pressure surface, eddies are generated, which also increases the flow loss of the airflow. Summary of the Invention

[0004] One of the technical problems solved by this invention is to provide a centrifugal impeller that can reduce the generation of eddies on the pressure surface, increase the working capacity of the centrifugal impeller, and make the static pressure capacity of the centrifugal impeller higher.

[0005] The second technical problem solved by this invention is to provide a centrifugal fan that can increase the working capacity of the centrifugal fan and make the static pressure capacity of the centrifugal fan higher.

[0006] The third technical problem solved by this invention is to provide a device that uses a centrifugal fan, which can increase the working capacity of the centrifugal fan and make the static pressure capacity of the centrifugal fan higher.

[0007] The first technical problem mentioned above is solved by the following technical solution:

[0008] A centrifugal impeller includes a connecting disc and multiple blades. The connecting disc has multiple blades arranged at intervals along the circumference of the connecting disc on at least one axial side. The thickness of the blades gradually increases from the inside to the outside along the radial direction of the connecting disc.

[0009] An airflow channel is formed between two adjacent blades. The width of the airflow channel gradually increases and then gradually decreases from the inside to the outside along the radial direction of the connecting disk. The arc length of the airflow channel along the circumference of the connecting disk is the width of the airflow channel.

[0010] The centrifugal impeller described in this invention has the following advantages compared with the prior art:

[0011] In this invention, the blades are configured with a non-uniform thickness blade structure. The thickness of the blades gradually increases from the inside to the outside along the radial direction of the connecting plate, and the width of the airflow channel gradually increases and then gradually decreases from the inside to the outside along the radial direction of the connecting plate. This makes the width of the airflow channel near the outlet end slowly decrease, and the airflow channel between two adjacent blades forms an effective airflow buffer area, allowing the airflow to flow better in the airflow channel between two adjacent blades, reducing the generation of eddies on the pressure surface, reducing noise, and increasing the work capacity of the centrifugal impeller at high speed, making the static pressure capacity of the centrifugal impeller higher.

[0012] In one embodiment, the blade includes a pressure surface and a suction surface disposed opposite to each other along the circumference of the connecting disk. The projection of the pressure surface in a preset plane includes a pressure arc, and the projection of the suction surface in the preset plane includes a suction arc. The preset plane is perpendicular to the axial direction of the connecting disk.

[0013] The end point of the pressure arc away from the central axis of the connecting plate is the first outer end point, and the end point of the suction arc away from the central axis of the connecting plate is the second outer end point;

[0014] The arc length of the first outer endpoint and the second outer endpoint between two adjacent blades along the circumference of the connecting disk is S1. Among the adjacent blades, the arc length of the second outer endpoint corresponding to one blade and the second outer endpoint corresponding to the other blade along the circumference of the connecting disk is S2, where 0.45 < S1 / S2 ≤ 0.57.

[0015] In one embodiment, S1 = (360° / z) × π × (d1 / 2) / 180, where d1 represents the outer diameter of the blade and z represents the number of blades.

[0016] In one embodiment, the circle represented by the inner diameter of the blade is the inner circle, and the extension line of the suction arc near the central axis of the connecting disk intersects the inner circle at a first intersection point. The line connecting the first intersection point and the projection point of the central axis of the connecting disk on the preset plane is the first connecting line.

[0017] The circle represented by the outer diameter of the blade is the outer circle. The end of the pressure arc away from the central axis of the connecting plate intersects the outer circle at a second point. The line connecting the second intersection point and the projection point is the second connecting line. The angle between the first connecting line and the second connecting line corresponding to any blade is α.

[0018] The inlet angle of the suction surface is a1, the inlet angle of the pressure surface is a2, the outlet angle of the suction surface is b1, the outlet angle of the pressure surface is b2, a1>a2, b1+1.5×α<b2<b1+3×α.

[0019] In one embodiment, the straight line tangent to the pressure arc and passing through the projection point is a preset tangent, and the angle between the preset tangent corresponding to any blade and the second connecting line is β; 0.6≤β / α≤0.8.

[0020] In one embodiment, 63°≤a1<90°, 126°≤b1<130°;

[0021] And / or, 60°≤a2<90°, 126°<b2<150°.

[0022] In one embodiment, the outer diameter of the blade is d1, the inner diameter of the blade is d2, and 0.78≤d2 / d1≤0.9.

[0023] In one embodiment, the connecting disc and the blade are integrally molded injection structures, or the connecting disc and the blade are integrally molded die-cast structures.

[0024] The second technical problem mentioned above is solved by the following technical solution:

[0025] A centrifugal fan includes a motor, a volute, and a centrifugal impeller as provided in any of the above embodiments. The centrifugal impeller is rotatably mounted inside the volute, and the output shaft of the motor is connected to the centrifugal impeller to drive the centrifugal impeller to rotate.

[0026] Compared with the prior art, the centrifugal fan of the present invention has the following beneficial effects:

[0027] The centrifugal fan includes the aforementioned centrifugal impeller, with blades configured as non-uniform thickness blades. The blade thickness gradually increases from the inside to the outside along the radial direction of the connecting plate, and the width of the airflow channel gradually increases and then gradually decreases from the inside to the outside along the radial direction of the connecting plate. This causes the width of the airflow channel near the outlet end to decrease slowly, and the airflow channel between two adjacent blades forms an effective airflow buffer area, allowing the airflow to flow better within the airflow channel between two adjacent blades. This reduces the generation of eddies on the pressure surface, lowers noise, and increases the work capacity of the centrifugal impeller at high speeds, resulting in higher static pressure capacity of the centrifugal impeller.

[0028] The third technical problem mentioned above is solved by the following technical solution:

[0029] Equipment that uses centrifugal fans includes the centrifugal fans mentioned above, wherein the equipment that uses centrifugal fans is a gas-fired hot water equipment or a fume extraction equipment.

[0030] Compared with the prior art, the equipment using a centrifugal fan described in this invention has the following advantages:

[0031] The equipment using this centrifugal fan includes the aforementioned centrifugal fan. The blades of the centrifugal impeller are configured with a non-uniform thickness blade structure. The thickness of the blades gradually increases from the inside to the outside along the radial direction of the connecting plate, and the width of the airflow channel gradually increases and then gradually decreases from the inside to the outside along the radial direction of the connecting plate. This causes the width of the airflow channel near the outlet end to decrease slowly. The airflow channel between two adjacent blades forms an effective airflow buffer area, allowing the airflow to flow better within the airflow channel between two adjacent blades. This reduces the generation of eddies on the pressure surface, lowers noise, and increases the work capacity of the centrifugal impeller at high speeds, resulting in a higher static pressure capacity of the centrifugal impeller. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the centrifugal impeller provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the blade's projection in a preset plane provided in an embodiment of the present invention;

[0034] Figure 3 This is an axial schematic diagram of the blade provided in an embodiment of the present invention;

[0035] Figure 4 This is a partial schematic diagram of the blade provided in an embodiment of the present invention;

[0036] Figure 5 yes Figure 3 A magnified view of a portion of point N in the diagram;

[0037] Figure 6 yes Figure 3 A magnified view of a portion of point M in the middle;

[0038] Figure 7 A schematic diagram illustrating the noise level during the operation of a gas water heater using an existing centrifugal impeller;

[0039] Figure 8 This is a schematic diagram illustrating the noise during the operation of a gas water heater using the centrifugal impeller provided by this invention.

[0040] Figure 9 It is a velocity vector diagram of a gas water heater that uses an existing centrifugal impeller during operation;

[0041] Figure 10 yes Figure 9 A magnified view of a portion of the image;

[0042] Figure 11 This is a velocity vector diagram of a gas water heater using the centrifugal impeller provided by this invention during its operation.

[0043] Figure 12 Figure 11 A magnified view of a portion of the image.

[0044] In the picture:

[0045] 1. Connecting plate; 2. Blade; 21. Suction surface; 211. Suction arc; 22. Pressure surface; 221. Pressure arc; 23. Airflow channel; 24. Inner surface; 241. Inner intersection line; 25. Outer surface; 251. Outer projection; 26. Top surface;

[0046] A. First outer endpoint; B. Second outer endpoint; C. First intersection point; D. Second intersection point; O. Projection point;

[0047] 10. Outer circle; 20. Inner circle. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] Embodiments of the present invention provide a centrifugal impeller, a centrifugal fan including the centrifugal impeller, and equipment using the centrifugal fan. By reducing the generation of eddies on the pressure surface of the centrifugal impeller, the working capacity of the centrifugal impeller is increased, resulting in a higher static pressure capacity. The equipment using the centrifugal fan can be a gas-fired water heating system, such as a gas water heater, gas-fired boiler, or gas-fired heating boiler; it can also be a fume extraction system with oil fume extraction function, such as a range hood, a combined range hood and stove, or an integrated stove. In equipment using a centrifugal fan, the centrifugal fan is mainly used as an air supply device. The equipment using a centrifugal fan is not limited to gas-fired water heating systems and fume extraction systems; it can also be other equipment that uses the aforementioned centrifugal fan as an air supply device, and is not specifically limited here.

[0053] like Figures 1 to 3 As shown, the centrifugal fan also includes a motor and a volute. The centrifugal impeller is rotatably installed inside the volute. The output shaft of the motor is connected to the centrifugal impeller to drive the centrifugal impeller to rotate, so that the external airflow enters the volute through the air inlet of the centrifugal fan and is sent to the air outlet of the centrifugal fan by the centrifugal impeller.

[0054] The centrifugal impeller includes a connecting disk 1 and multiple blades 2. The connecting disk 1 has multiple blades 2 arranged at intervals along the circumference of the connecting disk 1 on at least one side. The thickness of the blades 2 gradually increases from the inside to the outside along the radial direction of the connecting disk 1. An airflow channel 23 is formed between two adjacent blades 2. The width of the airflow channel 23 gradually increases from the inside to the outside along the radial direction of the connecting disk 1 and then gradually decreases. The arc length of the airflow channel 23 along the circumference of the connecting disk 1 is the width of the airflow channel 23.

[0055] The thickness of the blade 2 gradually increases from the inside to the outside along the radial direction of the connecting plate 1, and the width of the airflow channel 23 gradually increases and then gradually decreases from the inside to the outside along the radial direction of the connecting plate 1. This causes the width of the airflow channel 23 near the outlet end to decrease slowly. The airflow channel 23 between two adjacent blades 2 forms an effective airflow buffer area, allowing the airflow to flow better within the airflow channel 23 between two adjacent blades 2. This reduces the generation of vortices on the pressure surface 22, lowers noise, and increases the work capacity of the centrifugal impeller at high speeds, resulting in a higher static pressure capacity of the centrifugal impeller.

[0056] In some embodiments, such as Figure 1 , Figure 2 and Figure 4As shown, the blade 2 includes a pressure surface 22 and a suction surface 21 arranged opposite each other along the circumference of the connecting disk 1. The projection of the pressure surface 22 in the preset plane includes a pressure arc 221, and the projection of the suction surface 21 in the preset plane includes a suction arc 211. The preset plane is perpendicular to the axial direction of the connecting disk 1. The endpoint of the pressure arc 221 away from the central axis of the connecting disk 1 is the first outer endpoint A, and the endpoint of the suction arc 211 away from the central axis of the connecting disk 1 is the second outer endpoint B. The arc length of the first outer endpoint A and the second outer endpoint B between two adjacent blades 2 along the circumference of the connecting disk 1 is S1. The arc length of the second outer endpoint B corresponding to one blade 2 and the second outer endpoint B corresponding to another blade 2 along the circumference of the connecting disk 1 is S2, where 0.45 < S1 / S2 ≤ 0.57.

[0057] If the ratio of S1 to S2 is too small, such as less than or equal to 0.45, the opening at the outlet of airflow channel 23 will be too small, increasing the airflow resistance and affecting the airflow volume. If the ratio of S1 to S2 is too large, such as greater than 0.57, the opening at the outlet of airflow channel 23 will be too large, affecting the airflow velocity. By limiting the ratio to 0.45 < S1 / S2 ≤ 0.57, it is beneficial to reduce S2 and avoid S2 being too small. This ensures that the airflow resistance, airflow volume, and airflow velocity are maintained, while suppressing the separation of airflow in airflow channel 23. This increases the working capacity of the centrifugal impeller at high speeds, resulting in higher static pressure capacity and improved working efficiency of the centrifugal impeller.

[0058] It should be noted that the ratio of S1 to S2 can be any value greater than 0.45 and less than or equal to 0.57. For example, the ratio of S1 to S2 can be any value among 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, and 0.57.

[0059] In some embodiments, S1 = (360° / z) × π × (d1 / 2) / 180, where d1 represents the outer diameter of blade 2 and z represents the number of blades 2. This setting facilitates the determination of S2 based on the specific values ​​of d1 and z of the centrifugal impeller, avoiding S2 being too large or too small.

[0060] In some embodiments, such as Figures 3 to 6 As shown, the circle represented by the inner diameter of blade 2 is the inner circle 20. The extension line of the suction arc 211 near the central axis of the connecting disk 1 intersects the inner circle 20 at the first intersection point C. The line connecting the first intersection point C and the projection point O of the central axis of the connecting disk 1 on the preset plane is the first connecting line L1.

[0061] The circle shown by the outer diameter of blade 2 is outer circle 10. The end of pressure arc 221 away from the central axis of connecting disk 1 intersects outer circle 10 at a second intersection point D. The line connecting the second intersection point D and projection point O is the second connecting line L2. The angle between the first connecting line L1 and the second connecting line L2 corresponding to any blade 2 is α. The inlet angle of suction surface 21 is a1, the inlet angle of pressure surface 22 is a2, the outlet angle of suction surface 21 is b1, the outlet angle of pressure surface 22 is b2, a1>a2, b1+1.5×α<b2<b1+3×α.

[0062] While limiting 0.45 < S1 / S2 ≤ 0.57 and a1 > a2, if b2 ≤ b1 + 1.5 × α, the extension direction of blade 2 will be too close to a straight line; if b2 ≥ b1 + 3 × α, blade 2 will bend too much and form vortices, which is not conducive to airflow and will also increase noise and wind resistance. By limiting b1 + 1.5 × α < b2 < b1 + 3 × α, the airflow is more smoothly flowing in the airflow channel 23, reducing the generation of vortices on the pressure surface 22, thereby improving the work capacity of the centrifugal impeller, making the static pressure capacity of the centrifugal impeller higher, and improving the working efficiency of the centrifugal impeller.

[0063] It should be noted that b2 can be any value greater than b1 + 1.5 × α and less than b1 + 3 × α. For example, b2 can be any value from b1 + 1.6 × α, b1 + 1.7 × α, b1 + 1.8 × α, b1 + 1.9 × α, b1 + 2.0 × α, b1 + 2.1 × α, b1 + 2.2 × α, b1 + 2.3 × α, b1 + 2.4 × α, b1 + 2.5 × α, b1 + 2.6 × α, b1 + 2.7 × α, b1 + 2.8 × α, and b1 + 2.9 × α. Preferably, b2 = b1 + 2.5 × α.

[0064] The blade 2 has two opposite sides along the radial direction of the connecting disk 1, namely the inner side 24 and the outer side 25. The inner side 24 is closer to the central axis of the connecting disk 1 than the outer side 25. One end of the inner side 24 along the circumference of the connecting disk 1 is smoothly connected to the suction surface 21 through an arc surface, and the other end is connected to the pressure surface 22 through an arc surface. One end of the outer side 25 along the circumference of the connecting disk 1 is smoothly connected to the suction surface 21 through an arc surface, and the other end is connected to the pressure surface 22 through an arc surface.

[0065] The inner surface 24 intersects the connecting disk 1 at an inner intersection line 241. The endpoints of the inner intersection line 241 along the circumference of the connecting disk 1 are E1 and F1, respectively. E1 is closer to the suction arc 211, and F1 is closer to the pressure arc 221. E1 and F1 lie on a circle centered at the projection point O, which is the inner circle 20. The projection of the outer surface 25 onto the preset plane is the outer projection 251. The endpoints of the outer projection 251 along the circumference of the connecting disk 1 are E2 and F2, respectively. E2 is closer to the suction arc 211, and F2 is closer to the pressure arc 221. E2 and F2 lie on a circle centered at the projection point O, which is the outer circle 10.

[0066] In some embodiments, such as Figure 4 As shown, the straight line tangent to the pressure arc 221 and passing through the projection point O is the preset tangent line L. The angle between the preset tangent line L corresponding to any blade 2 and the second connecting line L2 is β; 0.6≤β / α≤0.8. If β / α<0.6, the extension direction of blade 2 will be too close to a straight line; if β / α>0.8, blade 2 will bend and form vortices, which is not conducive to airflow and will also increase noise and wind resistance. By limiting 0.6≤β / α≤0.8, it is beneficial for the airflow to flow more smoothly in the airflow channel 23, reducing the generation of vortices on the pressure surface 22, thereby improving the work capacity of the centrifugal impeller, making the static pressure capacity of the centrifugal impeller higher, and improving the working efficiency of the centrifugal fan.

[0067] It should be noted that β / α can be any value greater than or equal to 0.6 and less than or equal to 0.8, such as any value among 0.6, 0.65, 0.7, 0.75, and 0.8. Preferably, β / α = 0.7.

[0068] In some embodiments, such as Figure 5 and Figure 6 As shown, 63°≤a1<90°, 126°≤b1<130°; 60°≤a2<90°, 126°<b2<150°. This setting facilitates the entry of airflow into the airflow channel 23 and the exit of airflow from the airflow channel 23, thereby improving the working capacity and efficiency of the centrifugal impeller.

[0069] a1 can be any angle greater than or equal to 63° and less than 90°, b1 can be any angle greater than or equal to 126° and less than 130°, a2 can be any angle greater than or equal to 60° and less than 90°, and b1 can be any angle equal to 126° and less than 150°. For example, a1 = 63°, b1 = 127°; a2 = 60°, b2 = 138°.

[0070] In some embodiments, such as Figure 3As shown, the outer diameter of blade 2 is d1, and the inner diameter of blade 2 is d2. 0.78≤d2 / d1≤0.9. This setting ensures that the length of the airflow channel 23 meets the requirements, thereby improving the work capacity of the centrifugal impeller, increasing the static pressure capacity of the centrifugal impeller, and improving the working efficiency of the centrifugal impeller.

[0071] If the ratio of d2 to d1 is too large, the centrifugal fan's resistance performance will be poor, and blade 2 will not provide sufficient acceleration, easily leading to low static pressure after the airflow passes through blade 2, resulting in stalling. If the ratio of d2 to d1 is too small, the airflow channel 23 will be too long, increasing flow losses. The airflow will undergo a longer acceleration process, easily deteriorating the aerodynamic performance of the centrifugal impeller. The ratio of d2 to d1 can be any value greater than or equal to 0.78 and less than 1, such as any value among 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, and 0.9. Preferably, d2 / d1 = 0.8.

[0072] In some embodiments, such as Figure 1 As shown, from one end of the blade 2 connected to the connecting disk 1 to the other end of the blade 2, the inner surface 24 gradually moves away from the central axis of the connecting disk 1 along the radial direction. The top surface 26 of the blade 2 at the end away from the connecting disk 1 smoothly connects to the inner surface 24 through an arc surface. Furthermore, from one end of the blade 2 connected to the connecting disk 1 to the other end of the blade 2, the top surface 26 of the blade 2 gradually moves away from the central axis of the connecting disk 1 along the radial direction. This arrangement facilitates airflow into the airflow channel 23, improves the work capacity of the centrifugal impeller, increases the static pressure capacity of the centrifugal impeller, and improves the working efficiency of the centrifugal impeller.

[0073] In some embodiments, such as Figure 1 As shown, the connecting disc 1 and the blade 2 are integrally molded injection-molded structures, simplifying the machining of the centrifugal impeller and reducing machining costs. In some other embodiments, the connecting disc 1 and the blade 2 can also be integrally die-cast structures.

[0074] In some embodiments, such as Figure 1 As shown, multiple blades 2 are provided on both sides of the axial direction of the connecting disk 1, and the blades 2 on both sides of the axial direction of the connecting disk 1 are arranged symmetrically about the connecting disk 1.

[0075] The centrifugal impellers used in gas water heaters (i.e., the new centrifugal impellers in the table) and the existing centrifugal impellers used in gas water heaters with blades of equal thickness (i.e., the original centrifugal impellers in the table) were tested. Specifically, the parameters of the centrifugal impellers used in gas water heaters are as follows: a1 = 127°, a2 = 138°, α = 5.5°, β = 7.9°, S1 = 3.53, S2 = 6.21, d = 93, z = 47. Detailed test data are shown in the table below.

[0076]

[0077] Comparing the data in the table, it can be seen that when the maximum static pressure of the original centrifugal impeller and the new centrifugal impeller is the same (air volume is 0), the speed of the centrifugal fan using the new centrifugal impeller decreases by 60 rpm; under the same air volume, the static pressure of the new centrifugal impeller increases by 7 Pa. Obviously, the new centrifugal impeller has a stronger working capacity at high speed and can achieve a higher static pressure effect.

[0078] Noise tests were conducted on centrifugal impellers described above applied to gas water heaters, as well as on centrifugal impellers with medium-thick blades from existing technologies applied to gas water heaters. Figure 7 This is a diagram illustrating the noise level during the operation of a gas water heater using an existing centrifugal impeller. Figure 8 This is a schematic diagram of the noise during the operation of a gas water heater using the centrifugal impeller provided by this invention. Figure 7 and Figure 8 This is a graph showing how noise changes over time. Figure 7 and Figure 8 The three curves represent noise levels at three different locations. The blue line indicates the noise directly in front of the gas water heater, while the other two lines represent the noise levels on the left and right sides. At the same rotational speed, taking a centrifugal impeller speed of 4053 rpm as an example, the average noise level directly in front of a gas water heater using an existing centrifugal impeller reaches 45.8 dB(A), while the average noise level directly in front of a gas water heater using the centrifugal impeller provided by this invention reaches 44.3 dB(A).

[0079] Velocity simulation tests were conducted on the aforementioned centrifugal impellers and existing centrifugal impellers with medium-thick blades. Figure 9 This is a velocity vector diagram of a gas water heater using an existing centrifugal impeller during operation. Figure 10 yes Figure 9 A partially enlarged schematic diagram, Figure 11 This is a velocity vector diagram of a gas water heater using a centrifugal impeller provided by the present invention during its operation. Figure 12 Figure 11 A magnified view of a portion of the image. (Comparison) Figure 9 and Figure 11 It can be observed that in existing centrifugal impellers, the speed difference between adjacent airflow channels 23 is relatively large, and the speed variation of airflow within a single airflow channel 23 is also large, resulting in vortices generated on the pressure surface 22, which increases the noise of the centrifugal impeller. In the centrifugal impeller provided by the present invention, the speed of adjacent airflow channels 23 is more uniform, and the speed of airflow within the airflow channel 23 between two adjacent blades 2 changes slowly and uniformly, which helps to reduce the noise of the centrifugal impeller.

[0080] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0081] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A centrifugal impeller, characterized in that, Includes a connecting disk (1), wherein the connecting disk (1) has at least one axial side provided with a plurality of blades (2) arranged at intervals along the circumference of the connecting disk (1); the thickness of the blades (2) gradually increases from the inside to the outside along the radial direction of the connecting disk (1); An airflow channel (23) is formed between two adjacent blades (2). The width of the airflow channel (23) gradually increases from the inside to the outside along the radial direction of the connecting disk (1) and then gradually decreases. The arc length of the airflow channel (23) along the circumference of the connecting disk (1) is the width of the airflow channel (23).

2. The centrifugal impeller according to claim 1, characterized in that, The blade (2) includes a pressure surface (22) and a suction surface (21) arranged opposite to each other along the circumference of the connecting disk (1). The projection of the pressure surface (22) in the preset plane includes a pressure arc (221), and the projection of the suction surface (21) in the preset plane includes a suction arc (211). The preset plane is perpendicular to the axial direction of the connecting disk (1). The end point of the pressure arc (221) away from the central axis of the connecting disk (1) is the first outer end point (A), and the end point of the suction arc (211) away from the central axis of the connecting disk (1) is the second outer end point (B). The arc length of the first outer endpoint (A) and the second outer endpoint (B) between two adjacent blades (2) along the circumference of the connecting disk (1) is S1; among the adjacent blades (2), the arc length of the second outer endpoint (B) corresponding to one blade (2) and the second outer endpoint (B) corresponding to the other blade (2) along the circumference of the connecting disk (1) is S2, 0.45<S1 / S2≤0.

57.

3. The centrifugal impeller according to claim 2, characterized in that, S1=(360° / z)×π×(d1 / 2) / 180, where d1 represents the outer diameter of blade (2) and z represents the number of blades (2).

4. The centrifugal impeller according to claim 2, characterized in that, The circle represented by the inner diameter of the blade (2) is the inner circle (20). The extension line of the suction arc (211) near the central axis of the connecting disk (1) intersects the inner circle (20) at the first intersection point (C). The line connecting the first intersection point (C) and the projection point (O) of the central axis of the connecting disk (1) on the preset plane is the first connecting line (L1). The circle shown by the outer diameter of the blade (2) is the outer circle (10). The end of the pressure arc (221) away from the central axis of the connecting plate (1) intersects the outer circle (10) at a second intersection point (D). The line connecting the second intersection point (D) and the projection point (O) is the second connecting line (L2). The angle between the first connecting line (L1) and the second connecting line (L2) corresponding to any blade (2) is α. The inlet angle of the suction surface (21) is a1, the inlet angle of the pressure surface (22) is a2, the outlet angle of the suction surface (21) is b1, and the outlet angle of the pressure surface (22) is b2. a1>a2, b1+1.5×α<b2<b1+3×α.

5. The centrifugal impeller according to claim 4, characterized in that, The straight line that is tangent to the pressure arc (221) and passes through the projection point (O) is the preset tangent (L), and the angle between the preset tangent (L) and the second connecting line (L2) corresponding to any blade (2) is β; 0.6≤β / α≤0.

8.

6. The centrifugal impeller according to claim 3, characterized in that, 63°≤a1<90°, 126°≤b1<130°; And / or, 60°≤a2<90°, 126°<b2<150°.

7. The centrifugal impeller according to any one of claims 1 to 6, characterized in that, The outer diameter of the blade (2) is d1, and the inner diameter of the blade (2) is d2, where 0.78 ≤ d2 / d1 ≤ 0.

9.

8. The centrifugal impeller according to any one of claims 1 to 6, characterized in that, The connecting disc (1) and the blade (2) are integrally molded injection structures, or the connecting disc (1) and the blade (2) are integrally molded die-cast structures.

9. A centrifugal fan, characterized in that, The device includes a motor, a volute, and a centrifugal impeller as described in any one of claims 1 to 8, wherein the centrifugal impeller is rotatably mounted inside the volute, and the output shaft of the motor is connected to the centrifugal impeller to drive the centrifugal impeller to rotate.

10. Equipment using a centrifugal fan, characterized in that, Includes the centrifugal fan as described in claim 9, wherein the device using the centrifugal fan is a gas-fired hot water device or an oil fume extraction device.

Images