CN204493271U - A kind of centrifugal blower fan blade wheel - Google Patents

Abstract

A centrifugal fan impeller, including a disc and blades installed on the disc, characterized in that: the blades include wide blades and narrow blades, a blade path is formed between two adjacent wide blades, and the narrow blades Set in the blade passage, the length d1 of the blade passage in the circumferential direction, the distance d2 between the narrow blade and the pressure surface of the adjacent wide blade, satisfy the conditions: 1/4<d2/d1<1/2, the radial width of the narrow blade d3 , The radial width d4 of the wide blade satisfies the condition 1/3<d3/d4<2/3. The utility model has the advantages that: the impeller of the centrifugal fan designs the radial width of the narrow blade located in the blade passage as 1/3 to 2/3 of the radial width of the wide blade, and the distance between the narrow blade and the pressure surface of the adjacent wide blade It is designed to be 1/4 to 1/2 of the length of the blade path, which can effectively reduce the blockage at the blade inlet, reduce the expansion angle of the blade path, reduce the noise of the fan and reduce the loss of pressure and flow, that is, it can be used as little as possible. Under the premise of improving the aerodynamic performance of the fan, reduce the aerodynamic noise of the fan as much as possible.

Description

A centrifugal fan impeller

technical field

The utility model relates to a centrifugal fan, in particular to an impeller of the centrifugal fan.

Background technique

The impeller is an important part of the centrifugal fan. The working principle of the centrifugal fan is that the gas is sucked through the center of the impeller through the action of centrifugal force, and then flows through the leaf passage between the blades and flows out. The study found that the flow in the impeller channel of the centrifugal fan has a large degree of pressure diffusion, which is prone to air separation, especially near the suction surface at the rear of the impeller, which leads to uneven distribution of the circumferential air flow at the impeller outlet. Due to the high speed of the impeller, the uneven air flow at the outlet of the impeller will produce strong unsteady interference with the surrounding non-axisymmetrically distributed stationary parts, which is one of the main reasons for the aerodynamic noise of the centrifugal fan, especially the discrete noise, and has a great impact on The aerodynamic performance of the fan is adversely affected.

The energy loss of the fan is divided into flow loss, volume loss and mechanical loss, among which flow loss is the main one. Due to the viscosity of the gas, there are different degrees of friction and separation losses between the fan impeller and the volute, making it difficult for the fan efficiency to meet the ideal requirements. The centrifugal fan blade plays a major role in the actual flow in the impeller, and the blade profile and blade are reasonably optimized. Type, can effectively improve the fan and other comprehensive performance. The periodic action between the blade wake and the volute tongue is the reason why the fundamental frequency (blade passing frequency) noise becomes the main aerodynamic noise of the centrifugal fan.

At present, most of the research on the aerodynamic performance and aerodynamic noise of centrifugal fans at home and abroad focuses on changing the inclination angle of the volute tongue, the shape of the volute, the shape and number of blades, and so on. Some studies at home and abroad in recent years have shown that the reasonable arrangement of large and small blades can make the flow parameters of the centrifugal impeller outlet distributed more uniformly in the circumferential direction than the single row of blades, which is beneficial to reduce the unsteady impact loss and aerodynamic noise between the impeller and the stationary parts. In addition, aerodynamic performance and aerodynamic noise often have a mutual restrictive relationship. The improvement of one sometimes leads to the decline of the other. The method that can improve the aerodynamic performance and aerodynamic noise of centrifugal fans at the same time is the main goal of current research. In order to reduce the noise peak at the fundamental frequency, some scholars have proposed to design the impeller as a structure with unequal-spaced blades, so as to disperse the noise peak at the fundamental frequency, thereby reducing the overall noise level.

Utility model content

The technical problem to be solved by the utility model is to provide a centrifugal fan impeller which can effectively reduce the vortex of the air flow in the blade path in view of the above-mentioned existing technical situation.

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is: the impeller of the centrifugal fan includes a wheel disc and blades installed on the wheel disc, and is characterized in that: the blades include wide blades and narrow blades, and A leaf path is formed between the wide blades, and the narrow blade is arranged in the leaf path. The length d1 of the leaf path in the circumferential direction and the distance d2 between the narrow blade and the pressure surface of the adjacent wide blade satisfy the condition: 1/4<d2/ d1<1/2, the radial width d3 of the narrow blade and the radial width d4 of the wide blade satisfy the condition 1/3<d3/d4<2/3.

Preferably, the relationship between d1 and d2 and d3 and d4 satisfies the conditions: d2/d1=1/3 and d3/d4=1/2. According to the research, for the forward centrifugal fan, the larger the radial width of the narrow blade is, the higher the total pressure is, but the range of increase is reduced, and, within a certain range, the narrow blade moves from the suction side to the pressure side , both pressure and efficiency increase, but when the distance between the narrow blade and the pressure surface is 1/3 of the corresponding blade path length, the pressure close to the pressure surface decreases instead. Therefore, adopting the above-mentioned structure is more conducive to reducing or even eliminating the airflow vortex in the blade passage, thereby reducing the blockage at the blade inlet and reducing the expansion angle of the blade passage, thereby reducing the noise of the fan and reducing the pressure and flow loss.

Further preferably, the narrow blade is bent to the same side as the adjacent wide blade.

The narrow blades can have many different distribution structures. A preferred solution is that the wide blades and the narrow blades are distributed at intervals, that is, a narrow blade is provided in each of the blade passages. In this way, the number of narrow blades is the same as the number of wide blades.

Another preferred solution is that at least two wide blades are provided between the two adjacent narrow blades.

Another preferred solution is that four wide blades are arranged between the two adjacent narrow blades. That is, the number of narrow blades is 1/4 of the number of wide blades.

The narrow blades can be arranged at different positions of the blade passage, and a preferred solution is that the narrow blades are arranged at the air outlet of the blade passage.

Another preferred solution is that the narrow blades are arranged at the air inlet of the blade passage. Experiments have found that the airflow vortex of the entire blade path can be significantly reduced or even eliminated when narrow blades are used for the air inlet of the blade path.

Compared with the prior art, the utility model has the advantages that: the radial width of the narrow blade located in the blade passage is designed to be 1/3 to 2/3 of the radial width of the wide blade in the impeller of the centrifugal fan, and the narrow blade and the corresponding The distance between the pressure surface of the adjacent wide blade is designed to be 1/4 to 1/2 of the length of the blade path, which can effectively reduce the airflow vortex of the blade path, thereby effectively reducing the blockage at the blade inlet and reducing the expansion angle of the blade path, so that the fan's The noise is reduced and the loss of pressure and flow is small, that is, the aerodynamic noise of the fan can be reduced as much as possible on the premise of not losing the aerodynamic performance of the fan as much as possible.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment one;

Fig. 2 is a sectional view of Embodiment 1 of the utility model;

Fig. 3 is the enlarged schematic view of part A in Fig. 2;

Fig. 4 is the structural representation of the second embodiment of the utility model;

Fig. 5 is a structural schematic diagram of a third embodiment of the utility model;

Fig. 6 is a schematic structural view of Embodiment 4 of the utility model;

Fig. 7 is a schematic structural view of Embodiment 5 of the utility model;

Fig. 8 is a schematic structural diagram of Embodiment 6 of the present utility model.

Detailed ways

The utility model is described in further detail below in conjunction with the accompanying drawings.

Embodiment one:

As shown in Figures 1 to 3, the impeller in this embodiment includes a wheel disc 1 and wide blades 2 and narrow blades 3 installed on the wheel disc 1, and the wide blades 2 are evenly distributed on the outer circumference of the wheel disc 1 , A blade path 4 is formed between two wide blades 2 . The narrow blades 3 are arranged in the blade passage 4, and four wide blades 2 are arranged between two adjacent narrow blades 3, that is, the number of the narrow blades 3 is 1/4 of the number of the wide blades 2, such as for a conventional centrifugal fan impeller , if the number of wide blades 2 is 60, then the number of narrow blades 3 is 15. Also, the narrow blade 3 is bent to the same side as the adjacent wide blade 2 .

In addition, in this embodiment, the narrow vane 3 is arranged at the air inlet of the vane passage 4. Experiments have shown that after the narrow vane 3 is arranged at the air inlet of the vane passage, the air flow in the vane passage hardly generates vortices, which can effectively reduce the blockage at the entrance of the vane passage. , reduce the expansion angle of the blade path to reduce the separation loss, and at the same time reduce the slip coefficient to improve the work ability. Assume that the length of the blade path 4 in the circumferential direction is d1, the concave surface of the wide blade 2 is the pressure surface 21, the convex surface of the wide blade 2 is the suction surface 22, and the distance between the narrow blade 3 and the pressure surface 21 of the adjacent wide blade 2 is d2, Then the condition is satisfied: d2/d1=1/3. Assuming that the radial width of the narrow blade 3 is d3 and the radial width of the wide blade 2 is d4, then the condition: d3/d4=1/2 is satisfied. After adopting the above structure, the noise of the fan is reduced and the loss of pressure and flow is small, that is, the aerodynamic noise of the fan can be reduced as much as possible on the premise of not losing the aerodynamic performance of the fan as much as possible.

Embodiment two:

As shown in Figure 4, in the present embodiment, the narrow vane 3 is arranged at the air inlet of the blade passage 4, and two wide vanes 2 are arranged between two adjacent narrow vanes 3, that is, the number of the narrow vanes 3 is the wide vane. 2 half of the quantity. The rest of the structure is the same as that in Embodiment 1, and will not be described here.

Embodiment three:

As shown in Figure 5, in the present embodiment, the narrow vane 3 is arranged at the air inlet of the blade passage 4, and a piece of narrow blade 3 is arranged in each blade passage 4, that is, the number of the narrow blade 3 and the wide blade 2 same and spaced apart. The rest of the structure is the same as that in Embodiment 1, and will not be described here.

Embodiment four:

As shown in Figure 6, in this embodiment, the narrow blades 3 are arranged at the air outlet of the leaf passage 4, and a piece of narrow blade 3 is arranged in each leaf passage 4, that is, the number of the narrow blades 3 and the wide blades 2 are the same And interval distribution. Let the length of the blade path 4 be d1, set the distance between the narrow blade 3 and the pressure surface of the adjacent wide blade 2 to be d2, then satisfy d2/d1=1/3, set the radial width of the narrow blade 3 to be d3, and the wide blade 2 The radial width of is d4, and d3/d4=1/2 is satisfied.

Embodiment five:

As shown in Figure 7, in the present embodiment, the narrow blade 3 is arranged at the air outlet of the blade passage 4, and two wide blades 2 are arranged between two adjacent narrow blades 3, that is, the number of the narrow blades 3 is the width of the wide blade 2. half of the number, and the rest of the structure is the same as that in Embodiment 4, and will not be described here.

Embodiment six:

As shown in Figure 8, in this embodiment, the narrow blades 3 are arranged at the air outlet of the blade passage 4, and every three narrow blades 3 are separated by a blade passage 4 without a narrow blade 3, and the rest of the structure is the same as in Embodiment 4 The structure is the same and will not be described here.

The above descriptions are only preferred implementations of the present utility model. It should be pointed out that for those skilled in the art, without departing from the principle of the present utility model, various modifications or improvements can be made to the present utility model, such as narrow Other spacing distribution structures can also be used between the blade and the wide blade, and these are all considered within the protection scope of the present utility model.

Claims (8)

1. a centrifugal blower fan blade wheel, the blade comprising wheel disc (1) and be arranged on wheel disc, it is characterized in that: described blade comprises wide blade (2) and narrow blades (3), leaf road (4) is formed between two adjacent wide blades (2), described narrow blades (3) is located in leaf road (4), leaf road (4) length d1 in a circumferential direction, the distance d2 of narrow blades (3) and adjacent wide blade (2) pressure side (21), satisfy condition: 1/4<d2/d1<1/2, the radial width d3 of narrow blades (3), the radial width d4 of wide blade (2), satisfy condition 1/3<d3/d4<2/3.

2. centrifugal blower fan blade wheel according to claim 1, is characterized in that: the relation of described d1 and d2 and d3 and d4 satisfies condition: d2/d1=1/3 and d3/d4=1/2.

3. centrifugal blower fan blade wheel according to claim 1, is characterized in that: described narrow blades (3) and adjacent wide blade (2) are bending to the same side.

4. centrifugal blower fan blade wheel according to claim 1, it is characterized in that: described wide blade (2) is spaced apart with narrow blades (3), namely in each described leaf road (4), be equipped with a slice narrow blades (3).

5. centrifugal blower fan blade wheel according to claim 1, is characterized in that: between described two adjacent narrow blades (3), be provided with the wide blade of at least two panels (2).

6. centrifugal blower fan blade wheel according to claim 5, is characterized in that: between described two adjacent narrow blades (3), be provided with four wide blades (2).

7. the centrifugal blower fan blade wheel according to claim arbitrary in claim 1 to 6, is characterized in that: described narrow blades (3) is located at the air outlet place in leaf road (4).

8. the centrifugal blower fan blade wheel according to claim arbitrary in claim 1 to 6, is characterized in that: described narrow blades (3) is located at the suction port place in leaf road (4).