Multi-blade centrifugal fan impeller with arc-shaped front disc and multi-blade centrifugal fan

Abstract

The present invention relates to the field of centrifugal fans, and in particular to a multi-blade centrifugal fan impeller and a multi-blade centrifugal fan with an arc-shaped front disc. The impeller includes a front disc and a rear disc. The middle portion of the front disc is provided with an air intake port, and the rear disc is provided with a plurality of blades arranged in an array. The front disc is provided with an arc-shaped structure. In the direction from the air intake port to the rear disc, the front disc includes a front disc straight portion and a front disc circular portion connected to each other. An impeller clearance fitting portion is provided on the front disc straight portion at one end away from the front disc circular portion. The impeller clearance fitting portion is used to connect the impeller to a collector. The multi-blade centrifugal fan impeller and the multi-blade centrifugal fan with an arc-shaped front disc of the present invention have asymmetrical blades on both sides. The blades are straight and vertical at the contact end with the rear disc, and transition to an arc-shaped curvature at the contact end with the front disc. When airflow enters the impeller, it can flow along the arc direction of the blades, thereby reducing the vortex area and the impact area, effectively improving the fan pressure and efficiency of the multi-blade centrifugal fan, and reducing the fan noise generated by the swirling impact when the airflow enters.

Description

Technical Field

[0001] The present invention relates to the field of centrifugal fan industry, and in particular to a multi-blade centrifugal fan impeller with a curved front disc and a multi-blade centrifugal fan. Background Art

[0002] A multi-blade centrifugal fan is a type of centrifugal fan that uses a multi-blade impeller with a generally flat front disc. With its high air volume, low noise, and compact structure, multi-blade centrifugal fans are widely used in ventilation, air conditioning, and home appliance applications. However, existing multi-blade centrifugal fans often suffer from insufficient total pressure, low efficiency, and high noise levels, making them difficult to meet the demands of both the public and users.

[0003] Therefore, the performance of existing multi-blade centrifugal fans needs to be further improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-blade centrifugal fan impeller with an arc-shaped front disc and a multi-blade centrifugal fan, aiming to solve the problems of insufficient total pressure, low efficiency and high noise commonly existing in multi-blade centrifugal fans in the prior art.

[0005] To achieve the above-mentioned object, according to a first aspect of the present invention, a multi-blade centrifugal fan impeller having a curved front disc is provided, the impeller comprising a front disc and a rear disc, an air suction port being provided in the middle of the front disc, and a plurality of blades being arranged in an array around the rear disc;

[0006] The front disc is set to an arc-shaped structure. From the air intake to the rear disc, the front disc includes a front disc straight portion and a front disc arc portion that are connected to each other. An impeller clearance fitting portion is set on the end of the front disc straight portion away from the front disc arc portion. The impeller clearance fitting portion is used to connect the impeller and the collector.

[0007] Furthermore, the length L3 of the straight portion of the front disc is 10mm-10.2mm, the radius R2 of the arc portion of the front disc is 53mm-55mm, and the arc length is 79mm-82mm. The thickness L4 of the arc portion and the straight portion of the front disc are equal and are 3mm. The vertical distance L2 between the two ends of the arc portion of the front disc, from the air intake to the rear disc, is 54.3mm-54.5mm.

[0008] The impeller is cut with a plane passing through the central axis of the impeller, and the impeller clearance fitting portion forms an inverted L-shaped structure on the cross section. The height L5 of the impeller clearance fitting portion is 1.9mm-2.1mm, and the width L6 of the impeller clearance fitting portion is 4.5mm-5.5mm.

[0009] Furthermore, the blade includes a leading edge and a trailing edge, a first side edge connected between first ends of the leading edge and the trailing edge, and a second side edge connected between second ends of the leading edge and the trailing edge, the first side edge is a side edge close to the air suction port, the second side edge is a side edge away from the air suction port, and both the leading edge and the trailing edge are perpendicular to the rear disk;

[0010] The inlet angle ∠1 when the blade is installed is 109.3°-111.3°, the outlet angle ∠2 when the blade is installed is 164°-166°, and on the projection surface of the rear disc, the radius R1 of the blade is 39mm-41.5mm and the arc length is 66.7mm-71mm;

[0011] The impeller has a diameter φ1 of 570 mm, a diameter φ2 of the outer circle formed by the outer ends of all blades of 564 mm to 565 mm, a diameter φ3 of the inner circle formed by the inner ends of all blades of 458.6 mm to 459.5 mm, and a width L1 of the trailing edge of 187.5 mm to 188.5 mm.

[0012] The diameter of the air inlet φ4 is 451.6mm-452.4mm;

[0013] The number of blades is 42.

[0014] Further, φ2 is 564.6 mm, φ3 is 459.1 mm, φ4 is 452 mm, R1 is 40 mm and the arc length is 69.3 mm, R2 is 54 mm and the arc length is 80.5 mm, ∠1 is 110.3°, ∠2 is 165°, L1 is 188 mm, L2 is 54.4 mm, L3 is 10.1 mm, L5 is 2 mm, and L6 is 5 mm.

[0015] According to a second aspect of the present invention, a multi-blade centrifugal fan includes a volute and a collector fixedly arranged in the volute, and also includes the above-mentioned impeller, the impeller is arranged in the volute, and the impeller is connected to the collector through an impeller gap fitting portion.

[0016] Furthermore, the flow collector includes a connecting portion, an air guide portion, an air inlet, an air guide port, and a rectifying and anti-vortex ring. The flow collector is fixedly connected to the volute through the connecting portion. The connecting portion is annular and the inner circumference forms an air inlet. The outlet of the air guide portion forms the air guide port. One end of the rectifying and anti-vortex ring is fixedly connected to the connecting portion, and the other end of the rectifying and anti-vortex ring is fixedly connected to the air guide portion.

[0017] The current collector is cut with a plane passing through the central axis of the current collector. In the cross section and in the direction from the air inlet to the air guide outlet, the air guide portion includes an air guide portion arc segment and an air guide portion straight segment that are connected and arranged. The end of the air guide portion straight segment away from the air guide portion arc segment is provided with a current collector gap fitting portion, and the current collector gap fitting portion is matched with the impeller gap fitting portion.

[0018] The diameter φ5 of the air inlet is 564.5mm-567.5mm, the diameter of the air guide part gradually decreases and then remains unchanged in the direction away from the air inlet, the radius R3 of the arc section of the air guide part is 53mm-55mm and the arc length is 83mm-86.5mm, the length L7 of the straight section of the air guide part is 23.5mm-24.5mm, the diameter φ6 of the air guide port is 451.6mm-452.4mm, the diameter φ5 of the air inlet is 564.5mm-567.5mm, and the vertical distance L17 between the air inlet and the air guide port is 80mm-82mm.

[0019] Furthermore, the collector is cut with a plane passing through the central axis of the collector, and the gap fitting portion of the collector forms an inverted L-shaped structure on the cross section. The height L9 of the gap fitting portion of the collector is 1.4mm-1.6mm, the width L10 of the gap fitting portion of the collector is 9.5mm-10.5mm, and the thickness L8 of the arc section and the straight section of the air guide portion are equal and are 3mm.

[0020] Furthermore, the profile of the volute includes a first diffuser straight segment, a volute tongue segment, a first arc segment, a second arc segment, a third arc segment, a fourth arc segment, and a second diffuser straight segment that are tangentially connected in sequence; the first diffuser straight segment and the second diffuser straight segment enclose an air outlet, and the first arc segment, the second arc segment, the third arc segment, and the fourth arc segment are not cocentric;

[0021] A rectangular coordinate system is established with the center of the impeller as the coordinate origin. When the first diffuser straight line segment is located in the second quadrant, the coordinates of the center O1 of the first arc segment are (39.2, 39.2), the radius R5 is 318mm-320.5mm, and the arc length is 159mm-161mm. The coordinates of the center O4 of the second arc segment are (39.2, -39.2), the radius R6 is 396mm-399mm, and the arc length is 622mm-627m. m, the coordinates of the center O3 of the third arc segment are (-39.2, -39.2), the radius R7 is 474mm-478mm and the arc length is 745mm-750mm, the coordinates of the center O2 of the fourth arc segment are (-39.2, 39.2), the radius R8 is 552mm-557mm and the arc length is 867mm-875mm, the second diffuser straight line segment is perpendicular to the air outlet, and the first diffuser straight line segment is inclined along the air outlet.

[0022] Furthermore, the width L12 of the air outlet is 624mm-626mm, and the height L13 is 354mm-356mm;

[0023] The radius R4 of the volute tongue segment is 27.6mm-28.4mm and the arc length is 91mm-93mm. The length L11 of the first diffuser straight segment is 182mm-184mm, and the length L18 of the second diffuser straight segment is 394.5mm-397mm. The angle ∠3 between the tangent line of the volute tongue segment and the first diffuser straight segment and the first diffuser straight segment is 8.4°-8.6°. The narrowest width L16 between the second diffuser straight segment and the volute tongue segment is 437mm-439mm.

[0024] The width L14 of the volute is 1088mm-1092mm, and the height L15 of the volute is 969mm-971mm.

[0025] Furthermore, it also includes an air inlet flange, a motor and a machine base. The air inlet flange is fixedly arranged on the volute, the motor is connected to the impeller through the motor shaft, and the volute and the motor are both fixedly arranged on the machine base; the air inlet flange is annular and the inner diameter φ7 is 568mm-572mm.

[0026] The present invention provides a multi-blade centrifugal fan impeller with a curved front disc and a multi-blade centrifugal fan:

[0027] (1) The front disc of the impeller used in the multi-blade centrifugal fan adopts an arc design, which is different from the conventional straight front disc design. The blades on both sides are designed asymmetrically. The contact end of the blade and the rear disc is straight and vertical, and the contact end with the front disc has an arc curvature transition. The front end of the blade is designed to be arc-shaped to match the arc of the front disc. The arc curvature of the front disc and the blade inlet is optimized. When the airflow enters the impeller, it can flow along the arc direction of the blade, thereby reducing the vortex area and the impact area, effectively improving the fan pressure and efficiency of the multi-blade centrifugal fan, and reducing the fan noise generated by the swirling impact when the airflow enters;

[0028] (2) By matching the arc section of the air guide part and the arc section of the front disk designed with the same radius, and the impeller clearance fitting part and the collector clearance fitting part both designed in an inverted L shape, the air guide port of the collector is made smooth and straight, without misalignment and seamlessly connected to the air inlet of the arc-shaped front disk of the impeller. The collector and the impeller front disk are clearance-fitted in the axial and radial directions respectively, without the need for space distance and segment division, which reduces the friction of the air duct and realizes better installation and matching between the impeller and the collector through the impeller clearance fitting part and the collector clearance fitting part; by designing the rectifying anti-vortex ring, the generation of vortex in the fan can be effectively prevented, thereby improving the efficiency of the fan, and at the same time improving the strength of the air inlet to make it less likely to deform, making the air duct smoother;

[0029] (3) The use of logarithmic spiral volute arc transition ensures smooth and efficient airflow in the volute; by changing the curvature of the fan volute tongue and its longitudinal offset, the volute tongue is designed to be a pointed and deep structure, which can reduce the backflow area and effectively reduce noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the multi-blade centrifugal fan of the present invention;

[0031] Figure 2 Schematic diagram of the volute profile;

[0032] Figure 3 Schematic diagram of the volute from a top view;

[0033] Figure 4 Schematic diagram of the three-dimensional structure of the volute;

[0034] Figure 5 is a structural diagram of the impeller;

[0035] Figure 6 Schematic diagram of the side cross-sectional structure of the impeller;

[0036] Figure 7 for Figure 6 A partial enlarged view of point A in the middle;

[0037] Figure 8 Schematic diagram of the three-dimensional structure of the impeller;

[0038] Figure 9 is a side sectional view of the current collector;

[0039] Figure 10 for Figure 9 A partial enlarged view of point B in the middle;

[0040] Figure 11 is a performance curve diagram of the multi-blade centrifugal fan of the present invention;

[0041] Figure 12 It is a performance curve diagram of the comparison ratio.

[0042] Description of reference numerals:

[0043] Volute 1; first diffuser straight section 11; volute tongue section 12; first arc segment 13; second arc segment 14; third arc segment 15; fourth arc segment 16; second diffuser straight section 17; air outlet 18;

[0044] Impeller 2; blade 21; leading edge 211; trailing edge 212; front disc 22; front disc arc portion 221; front disc straight portion 222; impeller clearance fitting portion 223; rear disc 23; air inlet 24;

[0045] Current collector 3; connecting portion 31; air guide portion 32; air guide portion arc section 321; air guide portion straight section 322; current collector clearance fitting portion 323; air inlet 33; air guide port 34; rectifying anti-vortex ring 35;

[0046] Air inlet flange 4; motor 5; base 6. DETAILED DESCRIPTION

[0047] The present invention is described in detail below with reference to specific embodiments.

[0048] In the present invention, unless otherwise expressly specified and limited, when terms such as "set on", "connected", and "connected" appear, these terms should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrally connected; they can be directly connected or connected through one or more intermediate media. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The directional words that appear in the present invention are to better illustrate the characteristics of the features and the relationship between the features. It should be understood that when the placement direction of the present invention changes, the characteristics of the features and the direction of the relationship between the features also change accordingly. Therefore, the directional words do not constitute an absolute limitation on the characteristics of the features and the relationship between the features in space, but only play a relative limitation role.

[0049] The structural parameters adopted in the present invention are only for illustrating the technical solution of the present invention. That is, based on the basic structural parameters of the present invention, reasonable proportional scaling can be performed in actual production (for example, when the diameter of the impeller is 570 mm, it can be scaled 0.1-30 times, etc.), and such reasonable proportional scaling also falls within the scope of protection of the present invention.

[0050] See also Figure 1-12 According to a first aspect of the present invention, a multi-blade centrifugal fan impeller with an arc-shaped front disk is provided, and the impeller 2 includes a front disk 22 and a rear disk 23. An air suction port 24 is provided in the middle of the front disk 22, and a plurality of blades 21 are arranged in an array around the rear disk 23; the front disk 22 is provided with an arc-shaped structure, and in the direction from the air suction port 24 to the rear disk 23, the front disk 22 includes a front disk straight portion 222 and a front disk arc portion 221 that are connected and arranged, and an impeller gap fitting portion 223 is provided on the end of the front disk straight portion 222 away from the front disk arc portion 221, and the impeller gap fitting portion 223 is used to connect the impeller 2 and the collector 3.

[0051] Through the above technical solution, the impeller front disk 22 used for the multi-blade centrifugal fan adopts an arc-shaped design, which is different from the conventional straight front disk design. The blades 21 on both sides are asymmetrically designed. The contact end of the blade 21 with the rear disk 23 is straight and vertical, and the contact end with the front disk 22 has an arc-shaped curvature transition. The front end of the blade 21 is designed to be arc-shaped and consistent with the arc of the front disk 22. The arc curvature of the entrance of the front disk 22 and the blade 21 is optimized. When the airflow enters the impeller 2, it can flow along the arc direction of the blade 21, thereby reducing the vortex area and the impact area, effectively improving the fan pressure and efficiency of the multi-blade centrifugal fan, and reducing the fan noise caused by the swirling impact when the airflow enters.

[0052] In this embodiment, the length L3 of the straight portion 222 of the front disk is 10mm-10.2mm, the radius R2 of the arc portion 221 of the front disk is 53mm-55mm and the arc length is 79mm-82mm, the thickness L4 of the arc portion 221 and the straight portion 222 of the front disk are equal and are 3mm; in the direction from the air intake 24 to the rear disk 23, the vertical distance L2 between the two ends of the arc portion 221 of the front disk is 54.3mm-54.5mm; the impeller 2 is intercepted with a plane passing through the central axis of the impeller 2, and the impeller clearance fitting portion 223 forms an inverted L-shaped structure in the cross section, the height L5 of the impeller clearance fitting portion 223 is 1.9mm-2.1mm, and the width L6 of the impeller clearance fitting portion 223 is 4.5mm-5.5mm. Preferably, L3 is 10.1 mm, R2 is 54 mm and the arc length is 80.5 mm, L2 is 54.4 mm, L5 is 2 mm, and L6 is 5 mm.

[0053] In this embodiment, the blade 21 includes a leading edge 211 and a trailing edge 212, a first side connected between the first ends of the leading edge 211 and the trailing edge 212, and a second side connected between the second ends of the leading edge 211 and the trailing edge 212. The first side is the side close to the air inlet 24, and the second side is the side away from the air inlet 24. The leading edge 211 and the trailing edge 212 are both perpendicular to the rear disc 23. When the blade 21 is installed, the inlet angle ∠1 is 109.3°-111.3°, and the outlet angle ∠2 when the blade 21 is installed is 164°-166°. On the projection surface of the rear disc 23, The radius R1 of the blade 21 is 39mm-41.5mm, and the arc length is 66.7mm-71mm. The diameter φ1 of the impeller 2 is 570mm, the diameter φ2 of the outer circle formed by the outer ends of all the blades 21 is 564mm-565mm, the diameter φ3 of the inner circle formed by the inner ends of all the blades 21 is 458.6mm-459.5mm, and the width L1 of the trailing edge 212 is 187.5mm-188.5mm. The diameter φ4 of the air intake 24 is 451.6mm-452.4mm. The number of blades 21 is 42. Preferably, φ2 is 564.6mm, φ3 is 459.1mm, and φ4 is 452mm. R1 is 40mm, the arc length is 69.3mm, ∠1 is 110.3°, ∠2 is 165°, and L1 is 188mm.

[0054] According to a second aspect of the present invention, a multi-blade centrifugal fan includes a volute 1 and a collector 3 fixedly arranged in the volute 1, and also includes the above-mentioned impeller 2, the impeller 2 is arranged in the volute 1, and the impeller 2 is connected to the collector 3 through an impeller gap fitting portion 223.

[0055] In this embodiment, the collector 3 includes a connecting portion 31, an air guide portion 32, an air inlet 33, an air guide port 34 and a rectifying and anti-vortex ring 35. The collector 3 is fixedly connected to the volute 1 through the connecting portion 31. The connecting portion 31 is annular and the inner periphery forms an air inlet 33. The outlet of the air guide portion 32 forms an air guide port 34. One end of the rectifying and anti-vortex ring 35 is fixedly connected to the connecting portion 31, and the other end of the rectifying and anti-vortex ring 35 is fixedly connected to the air guide portion 32. The collector 3 is cut with a plane passing through the central axis of the collector 3. In the cross section and in the direction from the air inlet 33 to the air guide port 34, the air guide portion 32 includes an air guide portion circular arc segment 321 and an air guide portion straight line segment 322 that are connected and arranged. The air guide portion straight line segment 322 is away from the guide A collector gap fitting portion 323 is provided at one end of the wind portion arc segment 321, and the collector gap fitting portion 323 is matched with the impeller gap fitting portion 223; the diameter φ5 of the air inlet 33 is 564.5mm-567.5mm, and the diameter of the air guide portion 32 gradually decreases and then remains unchanged in the direction away from the air inlet 33. The radius R3 of the air guide portion arc segment 321 is 53mm-55mm and the arc length is 83mm-86.5mm. The length L7 of the straight section 322 of the air guide portion is 23.5mm-24.5mm. The diameter φ6 of the air guide port 34 is 451.6mm-452.4mm, and the vertical distance L17 between the air inlet 33 and the air guide port 34 is 80mm-82mm. Preferably, φ5 is 566 mm, R3 is 54 mm and the arc length is 84.8 m, L7 is 24 mm, φ6 is 452 mm, and L17 is 81 mm.

[0056] In this embodiment, when the current collector 3 is cut along a plane passing through the central axis of the current collector 3, the current collector clearance fit portion 323 forms an inverted L-shaped structure in the cross section. The height L9 of the current collector clearance fit portion 323 is 1.4 mm to 1.6 mm, and the width L10 of the current collector clearance fit portion 323 is 9.5 mm to 10.5 mm. The thickness L8 of the air guide portion arc segment 321 and the air guide portion straight segment 322 are equal and are both 3 mm. Preferably, L9 is 1.5 mm, and L10 is 10 mm.

[0057] Through the above technical scheme, in conjunction with the improvement of the impeller 2 and the volute 1, the collector 3 is designed with the same radius of the air guide arc section 321 and the front disk arc section 221, and the impeller clearance fitting part 223 and the collector clearance fitting part 323 are both designed in an inverted L shape, so that the air guide port 34 of the collector 3 is smooth and straight, without misalignment and seamlessly connected to the air intake port 24 of the arc-shaped front disk 22 of the impeller 2. The collector 3 and the impeller front disk are clearance-fitted in the axial and radial directions respectively, without the need to divide the spatial distance and segment, thereby reducing the friction of the air duct and achieving better installation and matching between the impeller 2 and the collector 3 through the impeller clearance fitting part 223 and the collector clearance fitting part 323; by designing the rectifying anti-vortex ring 35, it is possible to effectively prevent the generation of vortices in the fan, improve the efficiency of the fan, and at the same time improve the strength of the air inlet so that it is not easy to deform, making the air duct smoother.

[0058] In this embodiment, the profile of the volute 1 includes a first diffuser straight segment 11, a volute tongue segment 12, a first arc segment 13, a second arc segment 14, a third arc segment 15, a fourth arc segment 16, and a second diffuser straight segment 17, which are sequentially connected tangentially. The first diffuser straight segment 11 and the second diffuser straight segment 17 enclose an air outlet 18, and the first arc segment 13, the second arc segment 14, the third arc segment 15, and the fourth arc segment 16 are not cocentric.

[0059] A rectangular coordinate system is established with the center of the impeller 2 as the coordinate origin. When the first diffuser straight segment 11 is located in the second quadrant, the coordinates of the center O1 of the first arc segment 13 are (39.2, 39.2), the radius R5 is 318mm-320.5mm, and the arc length is 159mm-161mm. The coordinates of the center O4 of the second arc segment 14 are (39.2, -39.2), the radius R6 is 396mm-399mm, and the arc length is 622mm-627mm. The coordinates of the center O3 of the third arc segment 15 are (-39.2, -39.2), the radius R7 is 474mm-478mm and the arc length is 745mm-750mm. The coordinates of the center O2 of the fourth arc segment 16 are (-39.2, 39.2), the radius R8 is 552mm-557mm and the arc length is 867mm-875mm. The second diffuser straight segment 17 is arranged perpendicular to the air outlet 18, and the first diffuser straight segment 11 is arranged obliquely along the air outlet 18.

[0060] Preferably, a rectangular coordinate system is established with the center of the impeller 2 as the coordinate origin. When the first diffuser straight segment 11 is located in the second quadrant, the coordinates of the center O1 of the first arc segment 13 are (39.2, 39.2), the radius R5 is 319.2 mm, and the arc length is 160 mm. The coordinates of the center O4 of the second arc segment 14 are (39.2, -39.2), the radius R6 is 397.6 mm, and the arc length is 624.5 mm. The coordinates of the center O3 of the third arc segment 15 are (-39.2, -39.2), the radius R7 is 476 mm, and the arc length is 747.7 mm. The coordinates of the center O2 of the fourth arc segment 16 are (-39.2, 39.2), the radius R8 is 554.4 mm, and the arc length is 870.8 mm.

[0061] In this embodiment, the width L12 of the air outlet 18 is 624mm-626mm, and the height L13 is 354mm-356mm; the radius R4 of the volute tongue segment 12 is 27.6mm-28.4mm and the arc length is 91mm-93mm, the length L11 of the first diffuser straight segment 11 is 182mm-184mm, and the length L18 of the second diffuser straight segment 17 is 394.5mm-397mm. A tangent is drawn to the volute tongue segment 12 with the tangent point between the volute tongue segment 12 and the first arc segment 13 as the tangent point. The angle ∠3 between the tangent and the first diffuser straight segment 11 is 8.4°-8.6°. The narrowest width L16 between the second diffuser straight segment 17 and the volute tongue segment 12 is 437mm-439mm; the width L14 of the volute 1 is 1088mm-1092mm, and the height L15 of the volute 1 is 969mm-971mm. Preferably, L12 is 625 mm, height L13 is 355 mm, R4 is 28 mm and arc length is 92.1 mm, L11 is 183.1 mm, L18 is 395.8 mm, ∠3 is 8.51°, L16 is 438 mm, L14 is 1090 mm, and L15 is 970 mm.

[0062] This embodiment further includes an air inlet flange 4, a motor 5, and a base 6. The air inlet flange 4 is fixedly mounted on the volute 1. The motor 5 is drivingly connected to the impeller 2 via a motor shaft. The volute 1 and the motor 5 are both fixedly mounted on the base 6. The air inlet flange 4 is annular and has an inner diameter φ7 of 568 mm to 572 mm. Preferably, φ7 is 570 mm.

[0063] Through the above technical solution, the arc transition of the logarithmic spiral volute 1 is adopted to ensure smooth and efficient airflow in the volute 1; by changing the curvature of the fan volute tongue and its longitudinal offset, the volute tongue is designed to be a pointed and deep structure, which can reduce the backflow area and effectively reduce noise.

[0064] In order to verify this embodiment, based on the preferred structural parameters provided in this embodiment, a multi-blade centrifugal fan with a multi-blade centrifugal fan impeller having a curved front disk and an impeller 2 having a diameter of 570 mm was tested as a test example. At the same time, a multi-blade centrifugal fan with a traditional straight front disk and an impeller 2 having a diameter of 570 mm was tested as a comparative example. The test results were converted to the atmospheric pressure of 101325 Pa, the atmospheric temperature of 20°C, the fan speed of 960 r / min, and the medium density of 1.2 kg / m 3 The test data under the test conditions, the test case obtained the test data shown in Table 1 and Figure 11 The performance curve shown in Table 2 is obtained as a comparative example. Figure 12 The performance curve shown is based on volume flow as the horizontal axis. In the performance curve, qvsglGu is the volume flow, LAGu is the A sound level, ηr is the fan efficiency, PrGu is the impeller power, pFGu is the total pressure, and psFGu is the static pressure.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069] The test data and performance curves show that the control examples performed worse than the test examples in terms of total pressure, static pressure, fan efficiency, and A-sound level. In comparison, the test example achieved an optimal fan efficiency of 75.843% at a total pressure of 1406.9 Pa and a A-sound level of 83.025 dB; the test example achieved an optimal fan efficiency of 61.047% at a total pressure of 1176.6 Pa and a A-sound level of 83.249 dB. The test examples generally had higher fan efficiency and higher total pressure than the control examples, while the A-sound level of the test examples generally decreased compared to the control examples.

[0070] Compared with the prior art, the multi-blade centrifugal fan impeller with a curved front disc and the multi-blade centrifugal fan of the present invention improve the problems commonly existing in the prior art of multi-blade centrifugal fans, such as insufficient total pressure, low efficiency and high noise.

[0071] In the absence of conflict, the above-mentioned embodiments and features thereof may be combined with each other.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A multi-blade centrifugal fan impeller with a curved front disc, the impeller comprising a front disc and a rear disc, the front disc having an air intake inlet in the middle and a plurality of blades arranged in an array around the rear disc, characterized in that: The front disc is configured as an arc-shaped structure. In the direction from the air intake to the rear disc, the front disc includes a front disc straight portion and a front disc arc portion connected to each other. An impeller clearance fitting portion is provided on the end of the front disc straight portion away from the front disc arc portion. The impeller clearance fitting portion is used to connect the impeller and the collector. The length L3 of the straight section of the front disc is 10mm-10.2mm. The radius R2 of the arc section is 53mm-55mm and the arc length is 79mm-82mm. The thickness L4 of the arc section and the straight section of the front disc are equal and are 3mm. The vertical distance L2 between the two ends of the arc section of the front disc, from the air intake to the rear disc, is 54.3mm-54.5mm. The impeller is cut with a plane passing through the central axis of the impeller. The impeller clearance fit portion forms an inverted L-shaped structure in the cross section. The height L5 of the impeller clearance fit portion is 1.9mm-2.1mm, and the width L6 of the impeller clearance fit portion is 4.5mm-5.5mm. The blade includes a leading edge and a trailing edge, a first side edge connected between first ends of the leading edge and the trailing edge, and a second side edge connected between second ends of the leading edge and the trailing edge, the first side edge being a side edge close to the air suction port, the second side edge being a side edge away from the air suction port, and the leading edge and the trailing edge being perpendicular to the rear disk; The inlet angle ∠1 when the blade is installed is 109.3°-111.3°, the outlet angle ∠2 when the blade is installed is 164°-166°, and on the projection surface of the rear disc, the radius R1 of the blade is 39mm-41.5mm and the arc length is 66.7mm-71mm; The impeller has a diameter φ1 of 570 mm, a diameter φ2 of the outer circle formed by the outer ends of all blades of 564 mm to 565 mm, a diameter φ3 of the inner circle formed by the inner ends of all blades of 458.6 mm to 459.5 mm, and a width L1 of the trailing edge of 187.5 mm to 188.5 mm. The diameter of the air inlet φ4 is 451.6mm-452.4mm; The number of blades is 42.

2. The multi-blade centrifugal fan impeller with a curved front disk according to claim 1, characterized in that: φ2 is 564.6mm, φ3 is 459.1mm, φ4 is 452mm, R1 is 40mm and the arc length is 69.3mm, R2 is 54mm and the arc length is 80.5mm, ∠1 is 110.3°, ∠2 is 165°, L1 is 188mm, L2 is 54.4mm, L3 is 10.1mm, L5 is 2mm, and L6 is 5mm.

3. A multi-blade centrifugal fan comprising a volute and a flow collector fixedly disposed in the volute, characterized in that: It also includes the impeller according to any one of claims 1 to 2, the impeller is arranged in the volute, and the impeller is connected to the collector through an impeller clearance fit portion.

4. A multi-blade centrifugal fan according to claim 3, characterized in that: The collector includes a connecting portion, an air guide portion, an air inlet, an air guide port, and a rectifying and anti-vortex ring. The collector is fixedly connected to the volute through the connecting portion. The connecting portion is annular and the inner circumference forms an air inlet. The outlet of the air guide portion forms the air guide port. One end of the rectifying and anti-vortex ring is fixedly connected to the connecting portion, and the other end of the rectifying and anti-vortex ring is fixedly connected to the air guide portion. The current collector is cut with a plane passing through the central axis of the current collector. In the cross section and in the direction from the air inlet to the air guide outlet, the air guide portion includes an air guide portion arc segment and an air guide portion straight segment that are connected and arranged. The end of the air guide portion straight segment away from the air guide portion arc segment is provided with a current collector gap fitting portion, and the current collector gap fitting portion is matched with the impeller gap fitting portion. The diameter φ5 of the air inlet is 564.5mm-567.5mm, the diameter of the air guide part gradually decreases and then remains unchanged in the direction away from the air inlet, the radius R3 of the arc section of the air guide part is 53mm-55mm and the arc length is 83mm-86.5mm, the length L7 of the straight section of the air guide part is 23.5mm-24.5mm, the diameter φ6 of the air guide port is 451.6mm-452.4mm, and the vertical distance L17 between the air inlet and the air guide port is 80mm-82mm.

5. The multi-blade centrifugal fan according to claim 4, characterized in that: The collector is cut with a plane passing through the central axis of the collector, and the gap fitting portion of the collector forms an inverted L-shaped structure on the cross section. The height L9 of the gap fitting portion of the collector is 1.4mm-1.6mm, the width L10 of the gap fitting portion of the collector is 9.5mm-10.5mm, and the thickness L8 of the arc section and the straight section of the air guide portion are equal and are 3mm.

6. A multi-blade centrifugal fan according to claim 5, characterized in that: The profile of the volute includes a first diffuser straight segment, a volute tongue segment, a first arc segment, a second arc segment, a third arc segment, a fourth arc segment, and a second diffuser straight segment, which are sequentially connected tangentially; the first diffuser straight segment and the second diffuser straight segment enclose an air outlet, and the first arc segment, the second arc segment, the third arc segment, and the fourth arc segment are not cocentric; A rectangular coordinate system is established with the center of the impeller as the coordinate origin. When the first diffuser straight line segment is located in the second quadrant, the coordinates of the center O1 of the first arc segment are (39.2, 39.2), the radius R5 is 318mm-320.5mm, and the arc length is 159mm-161mm. The coordinates of the center O4 of the second arc segment are (39.2, -39.2), the radius R6 is 396mm-399mm, and the arc length is 622mm-627m. m, the coordinates of the center O3 of the third arc segment are (-39.2, -39.2), the radius R7 is 474mm-478mm and the arc length is 745mm-750mm, the coordinates of the center O2 of the fourth arc segment are (-39.2, 39.2), the radius R8 is 552mm-557mm and the arc length is 867mm-875mm, the second diffuser straight line segment is perpendicular to the air outlet, and the first diffuser straight line segment is inclined along the air outlet.

7. The multi-blade centrifugal fan according to claim 6, characterized in that: The width L12 of the air outlet is 624mm-626mm, and the height L13 is 354mm-356mm; The radius R4 of the volute tongue segment is 27.6mm-28.4mm and the arc length is 91mm-93mm. The length L11 of the first diffuser straight segment is 182mm-184mm, and the length L18 of the second diffuser straight segment is 394.5mm-397mm. The angle ∠3 between the tangent line of the volute tongue segment and the first diffuser straight segment and the first diffuser straight segment is 8.4°-8.6°. The narrowest width L16 between the second diffuser straight segment and the volute tongue segment is 437mm-439mm. The width L14 of the volute is 1088mm-1092mm, and the height L15 of the volute is 969mm-971mm.

8. The multi-blade centrifugal fan according to claim 7, characterized in that: It also includes an air inlet flange, a motor and a machine base. The air inlet flange is fixedly arranged on the volute. The motor is connected to the impeller through the motor shaft. The volute and the motor are both fixedly arranged on the machine base. The air inlet flange is annular and the inner diameter φ7 is 568mm-572mm.

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