CN101144484A - A cross-flow fan impeller - Google Patents

Abstract

The invention is a cross-flow fan impeller. It includes a left end cover (1), a right end cover (4), several middle spacer rings (3) and a set between the middle spacer rings (3) or between the middle spacer ring (3) and the end caps (1), (4) A number of blades (2), wherein the blades (2) are distributed according to the blade inclination angle beta=21±2°, and the number of blades (2) distributed on the impeller circumference is 30 to 40, and it does not matter whether they are distributed equidistantly or non-equidistantly , the circumferential spacing λ between two adjacent blades (2) satisfies: λ∈[6°, 15°]. Above-mentioned blade (2) just prolongs along the circumferential direction deflection angle by H=100 millimeter every time in the axial direction Proportional extension, deflection angle satisfy: ∈ [−0.12°, 0.12°]. On any cross-section of the blade (2), the blade width L is 12±2 mm, the blade chord height h is 2.5±0.8 mm, and the maximum thickness t in the middle of the blade is 1.3±0.5 mm. The invention has the optimal blade inclination angle, can greatly increase the air volume of the fan, and can reduce the noise during the operation of the fan.

Description

A cross-flow fan impeller

Technical field:

The invention relates to a fan impeller, specifically a cross-flow fan impeller with an optimal blade inclination angle, which belongs to the improvement technology of the existing cross-flow fan impeller.

Background technique:

At present, cross-flow fans are used in a wide range of applications. Among them, the indoor unit of the wall-mounted air conditioner relies on the impeller of the cross-flow fan to drive the airflow to exchange heat with the heat exchanger. The greater the air volume, the more obvious the heat exchange effect. Therefore, cross-flow fans require large air volume and low noise. However, in most current cross-flow fan impellers with a diameter D of 88±4 mm, the beta angle of the blades is generally 26±2°. As shown in Figure 2, the blade inclination angle beta is the angle between the line connecting the two ends of the blade and the line connecting the outer end of the blade and the center of the impeller on any cross section perpendicular to the impeller. Through numerical simulation and real test, it is found that for a cross-flow fan impeller with a diameter D of 88±4 mm, the blade inclination angle of 26±2° is not an optimal blade inclination angle.

Invention content:

The purpose of the present invention is to consider the above problems and provide a cross-flow fan impeller with an optimal blade inclination angle, which can greatly increase the air volume and reduce the noise.

The structure schematic diagram of the present invention is shown in Figure 1, comprises impeller left end cover (1), impeller right end cover (4), several middle spacer rings (3) and is arranged between middle spacer rings (3) or middle spacer ring ( 3) Several blades (2) between the left end cover (1) and the right end cover (4), wherein the blades (2) are distributed according to the blade inclination angle beta=21±2°.

On the cross section of the blade (2), the width L of the blade is 12±2 mm, the chord height h of the blade is 2.5±0.8 mm, and the maximum thickness t of the blade is 1.3±0.5 mm.

的比例延长，偏转角度满足： $\∂\∈[{-0.12}^0,{0.12}^0].$ Above-mentioned blade (2) just prolongs along the circumferential direction deflection angle by H=100 millimeter every time in the axial direction

Proportional extension, deflection angle satisfy: $\∂\∈[{-0.12}^0,{0.12}^0].$

The number of blades (2) distributed on the circumference of the impeller is 30-40, and the circumferential distance λ between two adjacent blades satisfies: λ∈[6°, 15°].

The diameter D of the impeller of the above-mentioned cross-flow fan is 88±4 mm.

Because the present invention adopts the structure with the optimal blade inclination angle, it not only greatly increases the air volume of the fan, but also reduces the noise during the operation of the fan. The invention is a cross-flow fan impeller with ingenious design, excellent performance, convenience and practicality.

Description of drawings:

Fig. 1 is the structural representation of cross-flow fan impeller of the present invention;

Fig. 2 is a cross-sectional view of a cross-flow fan impeller;

FIG. 3 is a partial enlarged view of A in FIG. 2 .

示意图。Figure 4 shows that when the blade is extended in the axial direction H=100mm, the deflection angle of the blade along the circumferential direction at the same time

schematic diagram.

Fig. 5 is a graph showing the influence of different blade inclination angles Beta on the air volume of the cross-flow fan.

FIG. 6 is a schematic diagram of cross-flow fan efficiency and corresponding air volume under different blade inclination angles Beta.

Detailed ways:

Example:

The schematic diagram of the structure of the cross-flow fan impeller of the present invention is shown in Figure 1, and Figure 2 is a cross-sectional view of the cross-flow fan impeller, where λ is the circumferential distance between two blades, and the beta angle is the blade inclination angle: Figure 3 is A in Figure 2 A partial enlargement of the . It includes the left end cover 1 of the impeller, the right end cover 4 of the impeller, several intermediate spacer rings 3 and several blades 2 not between the intermediate spacer rings 3 or between the intermediate spacer ring 3 and the left end cover 1 and right end cover 4, wherein the blades 2 are Blade inclination beta = 21 ± 2 ° distribution. On the cross section of the blade 2, the width L of the blade is 12±2 mm, the chord height h of the blade is 2.5±0.8 mm, and the maximum thickness t of the blade is 1.3±0.5 mm. The diameter D of the impeller of the above-mentioned cross-flow fan is 88±4 mm.

In this embodiment, the diameter D of the impeller of the cross-flow fan is: 88.8 mm, and the blades 2 are distributed between the middle spacer ring 3 or between the spacer ring 3 and the left end cover 1 and the right end cover 4 according to beta=21°. The blade width L of the above-mentioned blade 2 is 12 mm, the maximum chord height h of the blade is 2.5 mm, and the maximum thickness t of the blade is 1.2 mm.

示意图。其中，p₁为叶片端面在一隔环3所在面f上的圆周位置，p₂为叶片端面沿轴向延长H，并同时沿圆周方向偏转角度

后的位置，P₂′为p₂在面f上投影，p₂与P₂′之角的圆角间距就为偏转角度

。上述叶片2按在轴向上每延长H＝100毫米，就沿圆周方向偏转角度

的比例延长，偏转角度

满足： $\∂\∈[{-0.12}^0,{0.12}^0]$ 。本实施例中，上述叶片2在轴向上每延长时，叶片沿圆周方向偏转的角度

，即为直叶片叶轮。Figure 4 shows that when the blade is extended in the axial direction H=100mm, the deflection angle of the blade along the circumferential direction at the same time

schematic diagram. Among them, p ₁ is the circumferential position of the blade end surface on the surface f where the spacer ring 3 is located, and p ₂ is the axial extension H of the blade end surface and the deflection angle along the circumferential direction at the same time

After the position, P ₂ ′ is the projection of p ₂ on the surface f, and the fillet distance between p ₂ and P ₂ ′ is the deflection angle

. Above-mentioned blade 2 just prolongs along the circumferential direction deflection angle by H=100 millimeter every time in the axial direction

Proportional extension, deflection angle

satisfy: $\∂\∈[{-0.12}^0,{0.12}^0]$ . In this embodiment, when the above-mentioned blade 2 is extended in the axial direction, the deflection angle of the blade along the circumferential direction is

, which is a straight blade impeller.

The number of blades 2 distributed on the circumference of the impeller is 30-40, and the circumferential distance λ between two adjacent blades satisfies: λ∈[6°, 15°]. In this embodiment, the number of blades 2 distributed on the circumference of the impeller is 35, wherein the blades are distributed equidistantly, and the circumferential distance λ=360°/35=10.2857°.

In the numerical simulation, the blade inclination beta changes from 16° to 29°, and the corresponding changes in the air volume and efficiency of the cross-flow fan are shown in Figure 5 and Figure 6. Fig. 5 is a diagram showing the influence of different blade inclination angles Beta on the air volume of cross-flow fans, the abscissa is the blade inclination angle Beta, and the ordinate is the air volume, the unit is kg ³ /h. The abscissa in Figure 6 is the air volume, the unit is: kg ³ /h, and the ordinate is the efficiency. Under different blade inclination angles Beta, the best efficiency of the cross-flow fan and the corresponding flow rate determine a position in the coordinate system of this figure.

It can be seen from accompanying drawing 5 that the relationship between the flow rate and the blade inclination angle is a parabolic curve change, which is near the apex 21°. In the efficiency flow diagram of attached drawing 6, it can be seen more clearly that the blade inclination angle beta has an optimal area [19°~23°]. In this interval, the cross-flow fan has high efficiency and large flow.

According to the numerical simulation results, in the real test, we manufactured impellers with three different blade inclination angles of 17°, 21°, and 26°, and measured the air volume and noise of each impeller as shown in Table 1.

Table 1 Air volume noise of different impellers at different speeds

From the actual test results in Table 1 above, at the same speed, the air volume of the impeller with 21° blade inclination is nearly 30m ³ /h higher than that of the impeller with 26° blade inclination, while the noise level is similar.

After interpolation, it can be calculated that under the same air volume of 455m ³ /h, the noise of the impeller with 26° blade inclination is 36.6dB, the noise of 21° blade inclination is 35.1dB, and the noise of the impeller with 21° blade inclination is about 1.5dB smaller than that of the impeller with 26° blade inclination .

In addition, the impeller with 17° blade inclination in the table has slightly higher air volume and noise than the impeller with 26° blade inclination.

It can be seen from the above analysis that beta=21±2° blade inclination angle is indeed the optimal blade inclination angle.

Claims (5)

1. through-flow fan impeller, include impeller left end cap (1), impeller right end cap (4), in several spacer ring (3) and be located between the middle spacer ring (3) or middle spacer ring (3) and left end cap (1), right end cap (4) between some blades (2), it is characterized in that blade (2) presses blade tilt beta=21 ± 2 ° distribution.

2. axial-flow fan wheel according to claim 1 is characterized in that on the cross section of above-mentioned blade (2) that width of blade L is 12 ± 2 millimeters, and blade action h is 2.5 ± 0.8 millimeters, and maximum blade thickness t is 1.3 ± 0.5 millimeters.

3. through-flow fan impeller according to claim 1 and 2 is characterized in that above-mentioned blade (2) by every in the axial direction prolongation H=100 millimeter, and just along the circumferential direction the ratio of deflection angle  prolongs, and deflection angle  satisfies:  ∈ [0.12 °, 0.12 °].

4. through-flow fan impeller according to claim 3 is characterized in that the blade quantity that above-mentioned blade (2) distributes is 30～40 on circumference of impeller, the circumference spacing λ between adjacent two blades satisfies: λ ∈ [6 °, 15 °].

5. through-flow fan impeller according to claim 4, the diameter D that it is characterized in that above-mentioned through-flow fan impeller is 88 ± 4 millimeters.

Images