Centrifugal fan blade tip winglet structure

Abstract

The utility model discloses a blade tip winglet structure of a centrifugal fan, which belongs to the technical field of centrifugal fans and is characterized in that the distance between the front edge point of a wing-shaped plate and the windward side of a blade is larger than that between the front edge point of the wing-shaped plate and the leeside of the blade; an upper airfoil front edge part and an upper airfoil middle section part are sequentially arranged on the upper surface of the airfoil plate from the front edge point, the upper airfoil front edge part, the upper airfoil middle section part and the windward side form a pipeline expansion section shape, and a lower airfoil front edge part and a lower airfoil middle section part are sequentially arranged on the lower surface of the airfoil plate from the front edge point; the front edge part of the lower airfoil is of an arc-shaped structure and forms a pipeline contraction section shape with the leeside, the middle section part of the lower airfoil and the leeside form a pipeline expansion section shape, and the rear end point of the middle section part of the upper airfoil, the rear edge point of the airfoil plate and the rear end point of the middle section part of the lower airfoil form an arc-shaped flow guide part. The utilization rate of system power consumption can be improved, and the air volume is greatly increased while the noise reduction effect is improved.

Description

Technical Field

[0001] The utility model relates to a centrifugal fan blade tip winglet structure, belonging to the technical field of centrifugal fans. Background Art

[0002] When the impeller of a conventional centrifugal fan rotates, the centrifugal force generated by the impeller rotation is used to throw air out from between the blades. In this process, the speed between any adjacent blades is not effectively utilized, the internal energy loss between the blades is serious, and the overall performance is poor. In the prior art, a blade tip guide device is used to improve the above defects, but the existing blade tip guide device selects a conventional airfoil configuration, and the leading edge and the trailing edge are evenly distributed at adjacent blade tips at a vertical angle. The performance improvement is mainly due to the axial guide effect brought by the centrifugal force of the blade rotation. The system power consumption utilization rate is not high, the noise reduction effect is average, and the advantage of increasing the air volume is small. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a centrifugal fan blade tip winglet structure, which can improve the utilization rate of system power consumption, improve the noise reduction effect and significantly increase the air volume.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A centrifugal fan blade tip winglet structure comprises an wing plate, wherein the wing plate is arranged on a silent ring and located between two adjacent blades, the leading edge point of the wing plate is farther away from the windward surface of the blade than from the leeward surface of the blade, the trailing edge point of the wing plate is located at the middle width position adjacent to the blade tip, an upper wing leading edge portion and an upper wing middle section portion are sequentially arranged on the wing plate from the leading edge point, the upper wing leading edge portion and the upper wing middle section portion form a pipeline expansion cross-section shape with the windward surface, a lower wing leading edge portion and an upper wing middle section portion are sequentially arranged on the wing plate from the leading edge point, the lower wing leading edge portion is an arc-shaped structure and forms a pipeline contraction cross-section shape with the leeward surface, the upper wing middle section portion forms a pipeline expansion cross-section shape with the leeward surface, and the rear end point of the upper wing middle section portion, the trailing edge point of the wing plate and the rear end point of the upper wing middle section portion form an arc-shaped guide portion.

[0006] The angle between the tangent line at the leading edge point and the trailing edge point of the airfoil and the chord length is 50° to 75°.

[0007] The distance between the leading edge point of the airfoil and the windward side of the blade is 2 / 3 of the width of the adjacent blade tip, and the distance between the leading edge point of the airfoil and the leeward side of the blade is 2 / 3 of the width of the adjacent blade tip.

[0008] The maximum thickness of the airfoil is 0.22 mm, and the chord length is 2.1 mm.

[0009] The angle between the tangent line at the leading edge point and the trailing edge point of the airfoil and the chord length is 70°.

[0010] The leading edge point of the airfoil is at the same height as the blade.

[0011] The leading edge point height of the airfoil is less than the blade height by less than 0.4 mm.

[0012] The height of the airfoil plate is 1.2 mm to 2.4 mm.

[0013] The beneficial effects of the utility model are as follows: the utility model provides a centrifugal fan blade tip winglet structure, the distance between the leading edge point of the wing plate and the windward surface of the blade is greater than the distance from the leeward surface of the blade, the trailing edge point of the wing plate is located at the middle width position between adjacent blades, the leading edge of the upper wing and the middle section of the upper wing form a pipeline expansion cross-section shape with the windward surface, the leading edge of the lower wing is an arc structure and forms a pipeline contraction cross-section shape with the leeward surface, the middle section of the upper wing and the leeward surface form a pipeline expansion cross-section shape, and the high-speed airflow in the windward surface will blow over the upper wing surface. The internal pressure of the pipeline is reduced, the velocity gradient near the blade tip is reduced, and the tip vortex intensity is weakened. At the same time, as the pipeline expands, the airflow in the blade tip area is led out of the blade tip. Under the influence of the centrifugal force when the fan blade rotates, the airflow between the leeward surface and the lower wing surface will be pushed toward the blade tip as the pipeline contracts, and will flow out of the blade tip together with the high-speed airflow in the swept wind area of ​​the leading edge section of the lower wing. In addition, as the tip airflow can flow out, the speed near the tongue mouth is increased, the low-pressure area near the tongue mouth is increased, and the airflow flowing into the tongue mouth is reduced. Combining the above advantages, the utility model can improve the utilization rate of the system power consumption, reduce noise and significantly increase the air volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the position structure of a centrifugal fan blade tip winglet structure of the utility model;

[0015] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of the A position in the middle;

[0016] Figure 3 It is a schematic diagram of the cross-sectional structure of a centrifugal fan blade tip winglet structure of the utility model;

[0017] Figure 4 for Figure 3 Corresponding dimension drawing;

[0018] Figure 5 The dimensions and installation position diagram of the blade tip winglet corresponding to Example 1;

[0019] Figure 6 This is the working principle diagram of the blade tip winglet of the utility model;

[0020] Figure 7 This is a position diagram of the leading edge point of the blade tip winglet of the utility model;

[0021] Figure 8 The position diagram of the blade tip winglet at different rotation angles of Example 2;

[0022] Fig. 9 Figure 3 shows different lengths of blade tip winglets in Example 3;

[0023] Fig.10 This is a non-equal height position diagram of the leading edge point of the blade tip winglet and the blade in Example 4.

[0024] The reference numerals in the figure are as follows: 1-airfoil; 2-silent ring; 3-blade; 11-front edge of upper airfoil; 12-middle section of upper airfoil; 13-arc guide portion; 14-front edge of lower airfoil; 15-middle section of upper airfoil. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are not intended to limit the protection scope of the present invention. Specific embodiment 1

[0027] The utility model discloses a centrifugal fan blade tip winglet structure, comprising an airfoil plate 1, which is arranged on a silent ring 2 and located between two adjacent blades 3. The installation angle of the existing airfoil plate 1 is perpendicular to the silent ring 2, while in the utility model, the airfoil plate 1 is perpendicular to the silent ring 2. Figure 1 , Figure 2 and Figure 5 As shown, the distance between the leading edge of the airfoil 1 and the windward side of the blade 3 is greater than the distance between the leading edge of the airfoil 1 and the leeward side of the blade 3, and the trailing edge of the airfoil 1 is located at the middle width position of the adjacent blade tip 3. Figure 5 As shown, with reference to the XY plane, the distance between the leading edge point and the leeward side of blade 3 is 0.8 mm, i.e., 1 / 3 of the adjacent tip width, the distance between the leading edge point and the windward side of blade 3 is 2.4 mm, i.e., 2 / 3 of the adjacent tip width, and the trailing edge point is located at 1 / 2 of the adjacent tip width. The angle between the tangent line of the leading edge point and the trailing edge point of airfoil 1 and the chord length is 70°. Figure 7 As shown, one end of the trailing edge point of the airfoil 1 is located on one side of the silent ring 2 , and one end of the leading edge point extends to the height position of the blade 3 .

[0028] like Figure 3As shown, the upper wing leading edge portion 11 and the upper wing middle section portion 12 are sequentially arranged on the upper wing leading edge portion 1 from the leading edge point in the utility model. The upper wing leading edge portion 11 and the upper wing middle section portion 12 form a pipeline expansion cross-section shape with the windward surface. The lower wing leading edge portion 14 and the upper wing middle section portion 15 are sequentially arranged on the lower wing leading edge portion 1 from the leading edge point. The lower wing leading edge portion 14 is an arc-shaped structure and forms a pipeline contraction cross-section shape with the leeward surface. The upper wing middle section portion 15 forms a pipeline expansion cross-section shape with the leeward surface. The rear end point of the upper wing middle section portion 12, the trailing edge point of the wing plate 1 and the rear end point of the upper wing middle section portion 15 form an arc-shaped guide portion 13. Figure 6 As shown, the airflow in the high-speed area of ​​the windward surface will reduce the internal pressure of the duct when blowing over the upper wing surface, reduce the velocity gradient between the outer area of ​​the blade tip and the blade tip, and weaken the tip vortex. At the same time, as the duct expands, the airflow in this tip area is led out of the blade tip. Under the influence of the centrifugal force when the fan blade rotates, the airflow between the leeward surface and the lower wing surface will be pushed toward the blade tip as the duct contracts, and flow out of the blade tip together with the high-speed airflow in the swept wind area of ​​the leading edge section of the lower wing.

[0029] like Figure 4 As shown, the maximum thickness of the airfoil 1 is 0.22 mm, the chord length is 2.1 mm, and the height of the airfoil 1 is 2.0 mm. Specific embodiment 2

[0031] This embodiment is the same as the first embodiment, except that the angle between the tangent line at the leading edge and the trailing edge of the airfoil 1 and the chord length is between 50° and 75° and is not 70°. Figure 8 As shown, the coordinate point (9.1mm, 25.6mm) is defined as the rotation center point. The best placement position is rotated to both sides with the rotation center, each time with an interval of 5°. Between counterclockwise -15° and clockwise 5° (with the chord length angle at 70° as the initial position), the performance is improved compared to the conventional one, and the performance is best at the initial design position. Specific embodiment 3

[0033] This embodiment is the same as embodiment 1, and the position of the leading edge of the airfoil remains unchanged. Fig. 9 As shown, the only difference is that the trailing edge is extended and shortened along the trailing edge point. The minimum height is the same as the height of the silent ring, 1.2mm, and the maximum height is 2.4mm (excluding 2.0mm). The performance is improved within this range, but the performance is weaker than when the height is 2.0mm, that is, the initial design position. Specific embodiment 4

[0035] This embodiment is the same as embodiment 1. Fig.10 As shown, the only difference is that the optimal airfoil of Example 1 is sunk along the leading edge point as a whole by no more than 0.4 mm, and during this sinking process, the performance of Example 1 is very close to the original design position.

[0036] The above are only preferred implementations of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A centrifugal fan blade tip winglet structure, characterized in that: The invention comprises an airfoil (1), wherein the airfoil (1) is arranged on a silent ring (2) and is located between two adjacent blades (3), wherein the distance between the leading edge point of the airfoil (1) and the windward surface of the blade (3) is greater than the distance between the leading edge point of the airfoil (1) and the leeward surface of the blade (3), and the trailing edge point of the airfoil (1) is located at the middle width position of the adjacent blades (3), and the upper airfoil leading edge portion (11) and the upper airfoil middle section portion (12) are arranged on the airfoil (1) in sequence from the leading edge point. 12) forms a pipeline expansion cross-sectional shape with the windward surface, a lower wing leading edge portion (14) and a lower wing middle section portion (15) are sequentially arranged below the wing profile plate (1) starting from the leading edge point, the lower wing leading edge portion (14) is an arc-shaped structure and forms a pipeline contraction cross-sectional shape with the leeward surface, the lower wing middle section portion (15) forms a pipeline expansion cross-sectional shape with the leeward surface, and the rear end point of the upper wing middle section portion (12), the trailing edge point of the wing profile plate (1) and the rear end point of the lower wing middle section portion (15) form an arc-shaped guide portion (13).

2. According to claim 1, a centrifugal fan blade tip winglet structure is characterized in that: The angle between the tangent line at the leading edge point and the trailing edge point of the airfoil (1) and the chord length is 50° to 75°.

3. According to claim 1, a centrifugal fan blade tip winglet structure is characterized in that: The distance between the leading edge point of the airfoil (1) and the windward surface of the blade (3) is 2 / 3 of the width of the adjacent blade (3), and the distance between the leading edge point of the airfoil (1) and the leeward surface of the blade (3) is 2 / 3 of the width of the adjacent blade (3).

4. The centrifugal fan blade tip winglet structure according to claim 1, characterized in that: The maximum thickness of the airfoil plate (1) is 0.22 mm, and the chord length is 2.1 mm.

5. The centrifugal fan blade tip winglet structure according to claim 2, characterized in that: The angle between the tangent line at the leading edge point and the trailing edge point of the airfoil (1) and the chord length is 70°.

6. The centrifugal fan blade tip winglet structure according to claim 1, characterized in that: The leading edge point of the airfoil (1) is at the same height as the blade (3).

7. The centrifugal fan blade tip winglet structure according to claim 1, characterized in that: The leading edge point height of the airfoil plate (1) is less than the height of the blade (3) by less than 0.4 mm.

8. The centrifugal fan blade tip winglet structure according to claim 1, characterized in that: The height of the wing profile plate (1) is 1.2 mm to 2.4 mm.

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