阅读说明：本技术 一种前弯式风叶及叶轮及离心风机 (Forward-bending type fan blade, impeller and centrifugal fan ) 是由 付观井 唐秀文 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种前弯式风叶及叶轮及离心风机,其中,前弯式风叶包括叶片,所述叶片呈圆弧曲线设置,所述叶片展开并以所述叶片的底边一端点为坐标原点建立第一直角坐标系,所述第一直角坐标系的横轴为展开后的所述叶片的底边所在直线,在所述第一直角坐标系中依次取点,相邻的点之间通过平滑的线连接,直角坐标系的横轴与相邻的点的平滑连线而形成叶片的展开图；通过该结构的设置,能够有效的提高前弯式风机的出风效率、减少前弯式风机的喘振。(The invention discloses a forward-bent fan blade, an impeller and a centrifugal fan, wherein the forward-bent fan blade comprises a blade, the blade is arranged in a circular arc curve, the blade is unfolded, a first rectangular coordinate system is established by taking one end point of the bottom edge of the blade as an origin of coordinates, the transverse axis of the first rectangular coordinate system is the straight line where the bottom edge of the blade is located after the blade is unfolded, points are sequentially taken in the first rectangular coordinate system, adjacent points are connected through smooth lines, and the transverse axis of the rectangular coordinate system is smoothly connected with the adjacent points to form an unfolded drawing of the blade; through the arrangement of the structure, the air outlet efficiency of the forward-bent type fan can be effectively improved, and the surge of the forward-bent type fan is reduced.)

1. The utility model provides a forward-curved formula fan blade, includes blade (1), its characterized in that: the blades (1) are arranged in an arc curve, the blades (1) are unfolded, a first rectangular coordinate system (2) is established by taking an end point of the bottom edge of the blades (1) as a coordinate origin, the horizontal axis of the first rectangular coordinate system (2) is a straight line where the bottom edge of the unfolded blades (1) is located, and points (0, 0), (15.04, 72.31), (19.75, 141.79), (24.41, 139.26), (29.02, 136.99), (33.59 ), (42.63, 33.59), (47.11, 33.59), (33.59 ), (60.45, 33.59), (33.59 ), (73.38, 33.59), (77.55, 33.59), (33.59 ), (85.71, 33.59), (33.59, 120.2), (93.66, 33.59), (33.59, 119.36), (33.59, 36109, 118.59), (116.64, 118.58), (139.2, 118.58) and (139.2, 0), adjacent points are connected by smooth lines, and the horizontal axis of the rectangular coordinate system and the smooth lines of the adjacent points form the development view of the blade (1).

2. the forward-curved fan blade according to claim 1, wherein: establishing a second rectangular coordinate system (3), wherein the unit length of the second rectangular coordinate system (3) is the same as that of the first rectangular coordinate system (2), the plane of the first rectangular coordinate system (2) is perpendicular to the plane of the second rectangular coordinate system (3), points (-13.4,178.27), (0,185.1), (4.22,187.21), (8.41,189.22), (12.6,191.15), (16.78,192.99), (20.97,194.74), (25.15,196.42), (29.34,198.02), (33.53,199.53), (37.73,200.97), (41.95, 202.33), (46.14,203.63), (50.26,204.87), (54.33,206.06), (58.34,207.19), (62.3,208.29), (66.21,209.34), (70.09,210.34), (73.92,211.31), (77.72,212.23), (81.49,213.12), (85.24,213.97), (88.96,214.79), (92.66,215.56), (96.34,216.3), (100.01,217), (103.66,217.67), (107.29,218.31), (110.91, 218.91), (114.51, 219.48), (118.1,220.01), (118.59,220.08) are sequentially taken in the two rectangular coordinate systems, and the points taken in the second rectangular coordinate system (3) are sequentially in a transition smooth connection, the blade (1) is formed by bending a smooth connecting line corresponding to a point taken on the second rectangular coordinate system (3), and the point (0,185.1) on the second rectangular coordinate system (3) is the projection of a vertical line with the transverse mark of 19.75 on the first rectangular coordinate system (2) on the second rectangular coordinate system (3).

3. The forward-curved fan blade according to claim 2, wherein: the second rectangular coordinate system (3) is a smooth circular arc curve formed by connecting the taken points in sequence, and the radiuses r of the circular arc curves of the points taken in sequence on the second rectangular coordinate system (3) are 178.78, 185.1, 187.26, 189.41, 191.66, 193.72, 195.87, 198.02, 200.18, 202.33, 204.48, 206.64, 208.79, 210.94, 213.1, 215.25, 217.4, 219.56, 221.71, 223.87, 226.02, 228.17, 230.33, 232.48, 234.63, 236.79, 238.94, 241.09, 243.25, 245.4, 247.55, 249.71 and 250 in sequence.

4. An impeller, includes mutual front disk (4), back plate (5), front disk (4) set up along the horizontal direction, its characterized in that: the front-bending type fan blade further comprises the front-bending type fan blade as claimed in any one of claims 1 to 3, wherein the blade (1) is arranged between the front disc (4) and the rear disc (5), the front disc (4) and the rear disc (5) are parallel to each other, the bottom edge of the blade (1) is fixedly connected with the rear disc (5) and the front disc (4), the blade (1) is perpendicular to the rear disc (5), a third rectangular coordinate system (6) is established by using the central origin of the rear disc (5), the longitudinal axes of the blade (1) and the third rectangular coordinate system (6) are intersected, the end part of the blade (1) close to the center of the rear disc (5) is connected with the coordinate origin of the third rectangular coordinate system (6) to form a first line segment, the first line segment and the longitudinal axis of the third rectangular coordinate system (6) form a left slip angle, and the left slip angle is beta 1, the wind inlet angle of the blade (1) is beta 4, the wind outlet angle of the blade (1) is beta 4, the beta 4 is 36.55, the wind inlet angle of the blade (1) is beta 3, the beta 3 is 22.7, a connecting line of a coordinate origin of the third rectangular coordinate system (6) and the outer diameter of the blade (1) forms a second line segment, the second line segment and the longitudinal axis of the third rectangular coordinate system (6) form a right deflection angle beta 2, the beta 2 is 29.6, the blade (1) is provided with a plurality of blades (1), the blades (1) are arranged in a circumferential array with the coordinate origin of the third rectangular coordinate system (6), and the highest point of the blade (1) is close to the center of the rear disc (5).

5. An impeller according to claim 4, wherein: the front disc (4) is provided with an opening (7), the inner diameter of the opening (7) is C1, the inner diameter formed by the surrounding of the impellers is C2, the outer diameter formed by the surrounding of the impellers is C3, C3 is 500, C1 is 370.2, C2 is 362.6, and the unit lengths of the C1 and the C2 are the same as the unit length of the first rectangular coordinate system (2).

6. An impeller according to claim 4, wherein: the bending device is characterized in that an opening (7) of the front disc (4) is bent towards the direction back to the rear disc (5) to form a bent edge, the inner diameter of the bent edge is the inner diameter of the opening (7), a bent arc opening of the bent edge faces back to the center of the front disc (4), the bent arc radius is 20.42, a wall arc of the front disc (4) is arranged, the front disc (4) and the bent edge are in smooth transition, the arc radius of the wall of the front disc (4) is 62.5, a ratio arc opening of the front disc (4) faces back to the center of the front disc (4), and the unit lengths of the bent arc radius and the arc radius of the wall of the front disc (4) are equal to the unit length of the first rectangular coordinate system (2).

7. An impeller according to claim 4, wherein: the distance between the end faces of the front disc (4) and the rear disc (5) facing away from each other is 158, and the bit length of the distance between the end faces of the front disc (4) and the rear disc (5) facing away from each other is equal to the unit length of the first rectangular coordinate system (2).

8. An impeller according to claim 4, wherein: the blades (1) are provided with 16 blades.

9. The utility model provides a centrifugal fan, includes spiral case (8), have air intake and air outlet (17) on spiral case (8), its characterized in that: an impeller according to any one of claims 4 to 8, wherein an impeller according to any one of claims 4 to 8 is arranged in the volute (8), the front disc (4) faces the air inlet, a fourth rectangular coordinate system (18) is established on the end face of the volute (8) with the center of the air inlet as an origin, the direction of the air outlet (17) is the same as the longitudinal axis of the fourth rectangular coordinate system (18), the longitudinal axis of the fourth rectangular coordinate system (18) is vertically upward, a first square (9), a second square (10), a third square (11) and a fourth square (12) are respectively drawn in a first quadrant, a second quadrant, a third quadrant and a fourth quadrant of the fourth rectangular coordinate system, and one vertex angle of the first square (9), the second square (10), the third square (11) and the fourth square (12) coincides with the origin of the fourth rectangular coordinate system (18), the angle of the first square (9), the second square (10), the third square (11) and the fourth square (12) which is adjacent to a right-angle side is coincident with the horizontal axis of a fourth rectangular coordinate and the longitudinal axis of the fourth rectangular coordinate, the angles of the first square (9), the second square (10), the third square (11) and the fourth square (12) which are far away from the fourth rectangular coordinate are respectively the origin points to form a first circular arc (13), a second circular arc (14), a third circular arc (15) and a fourth circular arc (16), the adjacent first circular arc (13), the second circular arc (14), the third circular arc (15) and the fourth circular arc (16) are respectively tangent, the side lengths of the fourth square (12), the third square (11), the second square (10) and the first square (9) are respectively 58.1, 47.3, 38.4 and 31.3, the fourth circular arc (16), the third circular arc (15) and the fourth circular arc (16), The second circular arc (14) and the first circular arc (13) are 574.3, 469, 383.4 and 313.6 respectively to form the outer side wall of the volute (8).

10. the centrifugal fan according to claim 9, wherein: the distance from the side surface of the air outlet (17) far away from the origin of the fourth rectangular coordinate system (18) to the origin of the fourth rectangular coordinate system (18) is 622.4, the width of the air outlet (17) along the plane where the fourth rectangular coordinate system (18) is located is 436.1, and the distance from the end part of the air outlet (17) of the volute (8) to the fourth circular arc (16) is 350.7.

Technical Field

The invention relates to a fan, in particular to a forward-bent fan blade, an impeller and a centrifugal fan.

Background

In traditional centrifugal fan, the impeller front disc of fan also adopts conical and single arc structure, and the blade adopts single arc and narrow runner, and the air current energizing chance is little, and the air output has increased the air current resistance for a short time, and mobility and air current resistance when leading to the air-intake are big to produce the mobile vortex noise of air current, "surge" phenomenon appears easily, has increased the noise when fan operation.

Disclosure of Invention

the technical problem to be solved by the invention is as follows: at least one of the problems set forth above is solved.

The solution of the invention for solving the technical problem is as follows:

The front-bending type fan blade comprises blades, wherein the blades are arranged in a circular arc curve, a first rectangular coordinate system is established by taking one end point of the bottom edge of each blade as a coordinate origin, the transverse axis of the first rectangular coordinate system is the straight line where the bottom edge of each blade after being unfolded, and points (0, 0), (15.04, 72.31), (19.75), (24.41), (29.02), (29.31), (77), (42.63), (47.11), (60), (73), (66), (60.45), (85), (71), (73.38), (77.55), (85.71), (120.2), (93.66), (93, 36), (119), (109), (109.1), (109), (1), (77), (119), (36), (119), (b), (, (139.2, 118.58), (139.2, 0), adjacent points are connected by smooth lines, and the horizontal axis of the rectangular coordinate system forms a developed view of the blade by smooth connection of the adjacent points.

As a further improvement of the above solution, a second rectangular coordinate system is established, the unit length of the second rectangular coordinate system is the same as that of the first rectangular coordinate system, the plane of the first rectangular coordinate system is perpendicular to the plane of the second rectangular coordinate system, points (-13.4,178.27), (0,185.1), (4.22,187.21), (8.41,189.22), (12.6,191.15), (16.78,192.99), (20.97,194.74), (25.15,196.42), (29.34,198.02), (33.53,199.53), (37.73,200.97), (41.95, 202.33), (46.14,203.63), (50.26,204.87), (54.33,206.06), (58.34,207.19), (62.3,208.29), (66.21,209.34), (70.09,210.34), (73.92,211.31), (77.72,212.23), (81.49,213.12), (85.24,213.97), (88.96,214.79), (92.66,215.56), (96.34,216.3), (100.01,217), (103.66,217.67), (107.29,218.31), (110.91 ), (110.91) are sequentially taken in the two rectangular coordinate systems, points taken in the second rectangular coordinate system are sequentially smoothly transitionally connected, and the blade is bent corresponding to the smooth line of the points taken in the second rectangular coordinate system, the point (0,185.1) on the second rectangular coordinate system is the projection of the vertical line marked 19.75 on the first rectangular coordinate system on the second rectangular coordinate system.

As a further improvement of the above solution, the second rectangular coordinate system is a smooth circular arc curve formed by connecting the taken points in sequence, and the radii r of the circular arc curves of the points taken in sequence on the second rectangular coordinate system are 178.78, 185.1, 187.26, 189.41, 191.66, 193.72, 195.87, 198.02, 200.18, 202.33, 204.48, 206.64, 208.79, 210.94, 213.1, 215.25, 217.4, 219.56, 221.71, 223.87, 226.02, 228.17, 230.33, 232.48, 234.63, 236.79, 238.94, 241.09, 243.25, 245.4, 247.55, 249.71 and 250 in sequence.

An impeller comprises a front disc and a rear disc which are arranged in a horizontal direction, and further comprises a forward-bent fan blade, wherein the fan blade is arranged between the front disc and the rear disc, the front disc and the rear disc are parallel to each other, the bottom edge of the fan blade is fixedly connected with the rear disc and the front disc, the fan blade is perpendicular to the rear disc, a third rectangular coordinate system is established by using the center origin of the rear disc, the fan blade is intersected with the longitudinal axis of the third rectangular coordinate system, the end part of the fan blade close to the center of the rear disc is connected with the coordinate origin of the third rectangular coordinate system to form a first line segment, the first line segment and the longitudinal axis of the third rectangular coordinate system form a left deviation angle, the left deviation angle is beta 1, the beta 1 is 4.23 degrees, the wind outlet angle of the fan blade is beta 4, the beta 4 is 36.55 degrees, the wind inlet angle of the fan blade is beta 3, the beta 3 is 22.7 degrees, and the fan blade is characterized in that the left deviation angle is beta 1, the 4.23, the connecting line of a coordinate origin of the third rectangular coordinate system and the outer diameter of the blade forms a second line segment, the second line segment and the longitudinal axis of the third rectangular coordinate system form a right deflection angle beta 2, the angle beta 2 is 29.6 degrees, the blades are provided with a plurality of blades, the blades are arranged in a circumferential array with the coordinate origin of the third rectangular coordinate system, and the highest point of each blade is close to the center of the rear disc.

as a further improvement of the above scheme, an opening is formed in the front disc, the inner diameter of the opening is C1, the inner diameter surrounded by the plurality of impellers is C2, the outer diameter surrounded by the plurality of impellers is C3, C3 is 500, C1 is 370.2, C2 is 362.6, and the unit lengths of C1 and C2 are the same as the unit length of the first rectangular coordinate system.

As a further improvement of the above solution, the opening of the front plate is bent in a direction away from the rear plate to form a bent edge, the inner diameter of the bent edge is the inner diameter of the opening, the bent arc opening of the bent edge faces away from the center of the front plate, the bent arc radius is 20.42, the wall arc of the front plate is arranged, the front plate and the bent edge are in smooth transition, the arc radius of the wall of the front plate is 62.5, the arc opening of the front plate is opposite to the center of the front plate, and the unit lengths of the bent arc radius and the arc radius of the wall of the front plate are equal to the unit length of the first rectangular coordinate system.

As a further improvement of the above solution, the distance between the end surfaces of the front disc and the rear disc facing away from each other is 158, and the bit length of the distance between the end surfaces of the front disc and the rear disc facing away from each other is equal to the unit length of the first rectangular coordinate system.

As a further improvement of the scheme, 16 blades are arranged.

The centrifugal fan comprises a volute, wherein an air inlet and an air outlet are formed in the volute, an impeller is arranged in the volute, a front disc is opposite to the air inlet, a fourth rectangular coordinate system is established by taking the center of the air inlet as an original point on the end surface of the volute, the direction of the air outlet is the same as the longitudinal axis of the fourth rectangular coordinate system in the same direction, the longitudinal axis of the fourth rectangular coordinate system is vertically upward, a first square, a second square, a third square and a fourth square are respectively drawn by a first quadrant, a second quadrant, a third quadrant and a fourth quadrant of the fourth rectangular coordinate system, one vertex angle of the first square, the second square, the third square and the fourth square is coincided with the original point of the fourth rectangular coordinate system, and the first square, the second square, the third square and the fourth square are coincided with each other vertex angle of the fourth rectangular coordinate system, An adjacent right-angle side of the fourth square is coincided with a horizontal axis of a fourth rectangular coordinate and a longitudinal axis of the fourth rectangular coordinate, angles, far away from the fourth rectangular coordinate, of the first square, the second square, the third square and the fourth square are respectively used as an origin to form a first circular arc, a second circular arc, a third circular arc and a fourth circular arc, the adjacent first circular arc, the second circular arc, the third circular arc and the fourth circular arc are respectively tangent, the side lengths of the fourth square, the third square, the second square and the first square are respectively 58.1, 47.3, 38.4 and 31.3, and the side lengths of the fourth circular arc, the third circular arc, the second circular arc and the first circular arc are respectively 574.3, 469, 383.4 and 313.6 to form an outer side wall of the volute.

As a further improvement of the above scheme, a distance from a side of the air outlet away from the origin of the fourth rectangular coordinate system to the origin of the fourth rectangular coordinate system is 622.4, a width of the air outlet along a plane of the fourth rectangular coordinate system is 436.1, and a distance from an end of the air outlet of the volute to the fourth arc is 350.7.

the invention has the beneficial effects that: through the arrangement of the structure, the air outlet efficiency of the forward-bent type fan can be effectively improved, and the surge of the forward-bent type fan is reduced.

Drawings

In order to more clearly illustrate the technical solution in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is clear that the described figures are only some embodiments of the invention, not all embodiments, and that a person skilled in the art can also derive other designs and figures from them without inventive effort.

FIG. 1 is an exploded view of a centrifugal fan of the present invention;

FIG. 2 is a schematic view of the volute of the present invention;

FIG. 3 is a schematic diagram of a first rectangular coordinate system of the present invention;

FIG. 4 is a schematic diagram of a second rectangular coordinate system according to the present invention;

FIG. 5 is a front partial cross-sectional view of the impeller of the present invention;

Fig. 6 is a side sectional view of the impeller of the present invention.

Detailed Description

the conception, the specific structure, and the technical effects produced by the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings to fully understand the objects, the features, and the effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention. In addition, all the coupling/connection relationships mentioned herein do not mean that the components are directly connected, but mean that a better coupling structure can be formed by adding or reducing coupling accessories according to specific implementation conditions. All technical characteristics in the invention can be interactively combined on the premise of not conflicting with each other.

referring to fig. 1 to 6, a forward-curved fan blade includes a blade 1, where the blade 1 is disposed in an arc curve, the blade 1 is unfolded, a first rectangular coordinate system 2 is established with an end point of a bottom edge of the blade 1 as a coordinate origin, a horizontal axis of the first rectangular coordinate system 2 is a straight line where the bottom edge of the blade 1 is located after the blade 1 is unfolded, and points (0, 0), (15.04, 72.31), (19.75, 141.79), (24.41, 139.26), (29.02, 136.99), (33.59, 134.93), (38.13, 133.05), (42.63, 131.33), (47.11, 129.77), (51.58 ), (77.72), (51.58 ), (85.71, 51.58), (51.58, 120.2), (3693.66, 51.58), (51.58 ), (36109.109, 118.67), (112.88, 118.59), (116.64, 118.58), (139.2, 118.58), (139.2, 0), adjacent points are connected by a smooth line, and the horizontal axis of the rectangular coordinate system forms a developed view of the blade 1 by a smooth connection between adjacent points.

Through the arrangement of the structure, the air outlet efficiency of the forward-bent type fan can be effectively improved, and the surge of the forward-bent type fan is reduced.

Further as a preferred embodiment, a second rectangular coordinate system 3 is established, the unit length of the second rectangular coordinate system 3 is the same as that of the first rectangular coordinate system 2, the plane of the first rectangular coordinate system 2 is perpendicular to the plane of the second rectangular coordinate system 3, points (-13.4,178.27), (0,185.1), (4.22,187.21), (8.41,189.22), (12.6,191.15), (16.78,192.99), (20.97,194.74), (25.15,196.42), (29.34,198.02), (33.53,199.53), (37.73,200.97), (41.95, 202.33), (46.14,203.63), (50.26,204.87), (54.33,206.06), (58.34,207.19), (62.3,208.29), (66.21,209.34), (70.09,210.34), (73.92,211.31), (77.72,212.23), (81.49,213.12), (85.24,213.97), (88.96,214.79), (92.66,215.56), (96.34,216.3), (100.01,217), (103.66,217.67), (107.29,218.31), (110.91, 218.91), (114.51, 219.48), (118.1,220.01), (118.59,220.08) are sequentially taken in the two rectangular coordinate systems, the points taken in the second rectangular coordinate system 3 are smoothly transited, the blade 1 is formed by bending a smooth connecting line corresponding to a point taken on the second rectangular coordinate system 3, and a point (0,185.1) on the second rectangular coordinate system 3 is a projection of a vertical line with a transverse mark of 19.75 on the first rectangular coordinate system 2 on the second rectangular coordinate system 3.

In a further preferred embodiment, the second rectangular coordinate system 3 is a smooth circular arc curve formed by connecting points in sequence, and the radii r of the circular arc curves of the points in sequence in the second rectangular coordinate system 3 are 178.78, 185.1, 187.26, 189.41, 191.66, 193.72, 195.87, 198.02, 200.18, 202.33, 204.48, 206.64, 208.79, 210.94, 213.1, 215.25, 217.4, 219.56, 221.71, 223.87, 226.02, 228.17, 230.33, 232.48, 234.63, 236.79, 238.94, 241.09, 243.25, 245.4, 247.55, 249.71, and 250 in sequence.

An impeller comprises a front disc 4 and a rear disc 5 which are arranged mutually, the front disc 4 is arranged along the horizontal direction, the impeller further comprises a forward-bending type fan blade, a blade 1 is arranged between the front disc 4 and the rear disc 5, the front disc 4 is parallel to the rear disc 5, the bottom edge of the blade 1 is fixedly connected with the rear disc 5 and the front disc 4, the blade 1 is perpendicular to the rear disc 5, a third rectangular coordinate system 6 is established by using the central origin of the rear disc 5, the longitudinal axes of the blade 1 and the third rectangular coordinate system 6 are intersected, the end part, close to the center of a chassis, of the blade 1 of the third rectangular coordinate system 6 is connected with the coordinate origin of the third rectangular coordinate system 6 to form a first line segment, the first line segment and the longitudinal axis of the third rectangular coordinate system 6 form a left deviation angle, the left deviation angle is beta 1, the beta 1 is 4.23 degrees, the wind outlet angle of the blade 1 is β 4, β 4 is 36.55 °, the wind inlet angle of the blade 1 is β 3, β 3 is 22.7 °, a connecting line between a coordinate origin of the third rectangular coordinate system 6 and the outer diameter of the blade 1 forms a second line segment, the second line segment and the longitudinal axis of the third rectangular coordinate system 6 form a right deflection angle β 2, β 2 is 29.6 °, the blade 1 is provided with a plurality of blades 1, the plurality of blades 1 are arranged in a circumferential array with the coordinate origin of the third rectangular coordinate system 6, and the highest point of the blade 1 is arranged near the center of the rear disk 5.

in a further preferred embodiment, the front plate 4 is provided with an opening 7, an inner diameter of the opening 7 is C1, an inner diameter surrounded by the plurality of impellers is C2, an outer diameter surrounded by the plurality of impellers is C3, C3 is 500, C1 is 370.2, C2 is 362.6, and unit lengths of C1 and C2 are the same as the unit length of the first rectangular coordinate system 2.

In a further preferred embodiment, the opening 7 of the front plate 4 is bent in a direction away from the rear plate 5 to form a bent edge, the inner diameter of the bent edge is equal to the inner diameter of the opening 7, the bent arc opening of the bent edge faces away from the center of the front plate 4, the bent arc radius is 20.42, the wall of the front plate 4 is provided in an arc shape, the front plate 4 and the bent edge are in smooth transition, the arc radius of the wall of the front plate 4 is 62.5, the specific arc opening of the front plate 4 faces away from the center of the front plate 4, and the unit lengths of the bent arc radius and the arc radius of the wall of the front plate 4 are equal to the unit length of the first rectangular coordinate system 2.

In a further preferred embodiment, the distance between the end faces of the front disk 4 and the rear disk 5 facing away from each other is 158, and the length of the bit of the distance between the end faces of the front disk 4 and the rear disk 5 facing away from each other is equal to the unit length of the first rectangular coordinate system 2.

Further, as a preferred embodiment, 16 blades 1 are provided.

The centrifugal fan comprises a volute 8, wherein an air inlet and an air outlet 17 are formed in the volute 8, an impeller is arranged in the volute 8, the front disc 4 is opposite to the air inlet, a fourth rectangular coordinate system 18 is established by taking the center of the air inlet as an origin on the end surface of the volute 8, the direction of the air outlet 17 is in the same direction as the longitudinal axis of the fourth rectangular coordinate system 18, the longitudinal axis of the fourth rectangular coordinate system 18 is vertically upwards, a first square 9, a second square 10, a third square 11 and a fourth square 12 are respectively drawn in the first quadrant, the second quadrant, the third quadrant and the fourth quadrant of the fourth rectangular coordinate system, one vertex angle of the first square 9, the second square 10, the third square 11 and the fourth square 12 is coincided with the origin of the fourth rectangular coordinate system 18, and the first square 9, the second square 10, the third square 11 and the fourth square 12 are coincided with each other vertex angle of the origin of the fourth rectangular coordinate system 18, An adjacent right-angled side of the second square 10, the third square 11, and the fourth square 12 coincides with a horizontal axis of a fourth rectangular coordinate and a longitudinal axis of the fourth rectangular coordinate, angles of the first square 9, the second square 10, the third square 11, and the fourth square 12 away from the fourth rectangular coordinate are respectively an origin point and are used as a first circular arc 13, a second circular arc 14, a third circular arc 15, and a fourth circular arc 16, adjacent first circular arcs 13, second circular arcs 14, third circular arcs 15, and fourth circular arcs 16 are respectively tangent, the side lengths of the fourth square 12, the third square 11, the second square 10, and the first square 9 are respectively 58.1, 47.3, 38.4, and 31.3, and the side lengths of the fourth circular arc 16, the third circular arc 15, the second circular arc 14, and the first circular arc 13 are respectively 574.3, 469, 383.4, and 313.6, so as to form an outer side wall of the volute 8. The side length values of the fourth square 12, the third square 11, the second square 10 and the first square 9 are all the same as the unit length of the first rectangular coordinate system 2.

in a further preferred embodiment, a distance from a side of the air outlet 17 away from the origin of the fourth rectangular coordinate system 18 to the origin of the fourth rectangular coordinate system 18 is 622.4, a width of the air outlet 17 along a plane of the fourth rectangular coordinate system 18 is 436.1, and a distance from an end of the air outlet 17 of the scroll 8 to the fourth arc 16 is 350.7. The above values are all the same as the unit length of the first rectangular coordinate system 2.

in order to verify the scheme, a wind tunnel test is carried out on the centrifugal fan. The following results were obtained. When in test, the atmospheric pressure Pa is 100056Pa, the atmospheric temperature ta is 27.83 ℃, the relative humidity RH is 0.87, and the diameter of the impeller is 500 mm. The results are shown in table 1 below:

Table 1:

In the traditional centrifugal fan, only the traditional volute 8 and the traditional impeller are used for carrying out experiments, and during the experiments, the diameter of the traditional impeller is 500mm, the atmospheric pressure Pa is 100056Pa, the atmospheric temperature ta is 27 ℃, and the relative humidity RH is 0.87. The results of the experiment are shown in table 2 below.

Table 2:

The experiment was carried out in combination with the impeller of this scheme to adopt traditional spiral case 8, and the diameter of traditional impeller is 500mm, and atmospheric pressure Pa equals 100056Pa, and atmospheric temperature ta equals 27 ℃, and relative humidity RH equals 0.87. The results of the experiment are shown in table 3 below.

Table 3:

The spiral case 8 of this scheme of adoption is experimental with traditional impeller, and during the experiment, the diameter of traditional impeller is 500mm, and atmospheric pressure Pa is 100056Pa, and atmospheric temperature ta is 27 ℃, and relative humidity RH is 0.87. The results of the experiment are shown in table 4 below.

Table 4:

As can be seen from tables 1 to 4, the experimental data in table 1 have the best effect, and when the generated volume flows are close to each other, the impeller of the experimental object in table 1 has the lowest power in the same operating point, so that the effect of saving energy consumption can be effectively achieved, and meanwhile, the specific sound level a is also the lowest experimental data in table 1 in the same operating point, so that the noise is the lowest.

However, as can be seen from the above analysis in tables 1 to 4, when the impeller of the present scheme is applied to the conventional volute 8, compared with the conventional impeller and the conventional volute 8, the impeller has the same obvious performance improvement in fan efficiency and static efficiency, and can generate similar volume flow with less impeller power. However, when the volute 8 of the present solution is combined with a conventional impeller, the effect is significantly worse than the effect when the conventional impeller is combined with the conventional volute 8. However, in this embodiment, when the spiral case 8 of this embodiment is combined with the impeller of this embodiment, the optimal effect in each set of experiments is achieved.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the present invention is not limited to the details of the embodiments shown and described, but is capable of numerous equivalents and substitutions without departing from the spirit of the invention as set forth in the claims appended hereto.