CN213450988U

CN213450988U - Centrifugal impeller and ventilator thereof

Info

Publication number: CN213450988U
Application number: CN202022463753.XU
Authority: CN
Inventors: 裘霖富; 徐天赐; 张职锋; 马杰凯; 俞晓骏; 刘伟
Original assignee: Zhejiang Kemao Intelligent Electromechanical Co ltd
Current assignee: Zhejiang Kemao Intelligent Electromechanical Co ltd
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2021-06-15
Anticipated expiration: 2030-10-30

Abstract

The utility model relates to a centrifugal impeller and ventilation blower thereof, the impeller includes that head disk, back plate and even clamp are established a plurality of blades between head disk and the back plate, the space that adjacent blade and head disk, back plate enclose is the airflow channel in the impeller, and the air current is followed head disk axial gets into the impeller, through the runner between the blade after, flows from the impeller periphery, the head disk includes straight induction zone, main part segmental arc, straight export section, export turn-ups section in proper order from air current import to export, straight induction zone is straight tube-shape, straight export section is the ring form, the entrance point of main part segmental arc with the tangent connection of straight induction zone, the exit end of main part segmental arc with the tangent connection of straight export section.

Description

Centrifugal impeller and ventilator thereof

Technical Field

The utility model relates to a ventilation blower technical field, in particular to centrifugal impeller, the utility model discloses still relate to the ventilation blower including above-mentioned centrifugal impeller.

Background

The centrifugal impeller mainly comprises a rear disk, a front disk and a plurality of blades arranged between the rear disk and the front disk, wherein an inner hole of the front disk is an impeller inlet. The basic form of the front disk is a straight front disk, a conical front disk and an arc front disk. The cross-sectional shape of the front disc has a large influence on the flow state in the blade flow channel, so that the performance of the ventilator is remarkably influenced, and the impeller with high efficiency mostly adopts an arc-shaped front disc (usually adopting an arc shape). Generally, the radius r of the inboard front end of the front disk should be as large as possible to reduce separation and loss of the impeller inlet flow when turning. However, the enlarged radius of the front end of the front disc can cause the increase of the volume of the impeller, increase the cost and limit the use occasions, so that the length and the arc shape of the front disc of the impeller are improved in a limited range as much as possible, the front disc of the impeller can be more suitable for the airflow characteristics of a centrifugal impeller compared with the existing arc-shaped front disc of the impeller, the airflow turns smoothly, the flow field tends to be stable as much as possible, and the vortexes and the separation of the gas are reduced.

SUMMERY OF THE UTILITY MODEL

The centrifugal impeller has an airflow characteristic that, at the impeller inlet side, after a main airflow enters the impeller from the axial direction, the main airflow flows by two large turns: one is turning at 90 degrees from axial direction to radial direction, and the other is turning in circumferential direction formed by the action of rotating blades of the impeller on gas, namely, the gas flow near the inner diameter of the front disk is usually uneven, so that gas flow separation is easy to generate, the flow field in the impeller is further deteriorated, the efficiency of the impeller on the gas is influenced, and further, the pressure of the ventilator is reduced, and the power consumption is increased. Therefore, the arc turning radius at the inner diameter of the front disc is designed to be larger as much as possible, so that the airflow turns smoothly, and the flow field tends to be stable as much as possible, thereby reducing the swirl and separation of the gas.

On the other hand, inside the impeller, each fluid passage between the blades is surrounded by two adjacent blades, a front disk and a rear disk: the shape of the front disk, with the vane profile established, determines the axial width and flow area of the vane passage at each diameter, with a significant effect on the flow conditions within the vane passages, and it is generally desirable to create a uniformly decelerated flow within the vane passages so that the flow exits the impeller at a lower velocity at the tips at the vane outer diameter, with the width of the vane passages from the impeller inner diameter to the impeller outer diameter being progressively larger for centrifugal impellers, and the front disk being designed to be inclined toward the rear disk, i.e., with increasing diameter, the width of the vanes progressively decreasing-the vane exit width b-for constant velocity or deceleration flow passages₂Less than the width b of the blade inlet₁。

Based on the inside air current flow characteristic of above impeller, the utility model discloses mainly improve the inducer of impeller and the structure of inside main part section two parts through the design, reduce the air current and trun into radially at impeller inducer import department axial to and because of the rotatory circumferencial direction's that causes gas turn round, the swirl and the separation that cause. The utility model discloses on the basis of present widely used convex cross sectional shape front bezel, through the cross-section arc line shape of optimizing the front bezel, further optimize the gas flow state in impeller import department and the impeller blade way to improve the efficiency of impeller to gas doing work and then improve the aerodynamic performance and the efficiency of impeller and ventilation blower.

The utility model discloses a following technical scheme realizes above-mentioned purpose:

the utility model provides a centrifugal impeller, the impeller includes that front bezel, back plate and even clamp are established a plurality of blades between front bezel and the back plate, and the space that adjacent blade and front bezel, back plate enclose is the airflow channel in the impeller, and the air current is followed front bezel axial gets into the impeller, through the runner between the blade after, from the impeller periphery outflow, preceding dish is precedingThe dish includes straight import section, main part segmental arc, straight export section, export turn-ups section from the air current import to the export in proper order, straight import section is straight tube-shape, and straight export section is the ring form, the entrance point of main part segmental arc with straight import section is tangent to be connected, the exit end of main part segmental arc with straight export section is tangent to be connected, and the hole diameter of antetheca is D₀With a straight outlet section having an internal diameter D₂。

Further, the generatrix of the arc segment of the main body in rectangular coordinates satisfies the following equation:

u is the radial width of main part segmental arc, and v is the axial height of main part segmental arc crosses the axial parallel line that main part segmental arc exit end made the impeller obtains rectangular coordinate's x axle, crosses the radial parallel line that main part segmental arc entrance end made the impeller obtains rectangular coordinate's y axle, and the nodical original point O that is rectangular coordinate of the nodical point of x axle and y axle, and wherein, x, y satisfy: x is more than or equal to 0 and less than or equal to v, and y is more than or equal to u and less than or equal to 0.

Further, a straight line connecting the inlet end and the outlet end of the arc-shaped section of the main body forms an angle θ =30 ° -40 °, u =0.5 × (D) with the radial center line of the impeller₂~D₀) V = u × tg θ, and the horizontal distance from the origin O to the inner plane of the rear disk is "b₂+ v ", the perpendicular distance from the origin O to the impeller center line is" 0.5 XD₂”。

Further, the ratio of the axial height of the main body arc section to the radial width of the main body arc section is 0.6-0.8.

Further, the axial length s of the straight inlet section satisfies: s = (0.01 to 0.02) × D₂Wherein D is₂Is the outer diameter of the blade.

A ventilator comprises a centrifugal impeller and an air inlet, wherein the impeller is sleeved outside the air inlet, and the axial overlapping length of the impeller and the air inlet is t₁Satisfies the following conditions: t is t₁=(0.01~0.02)×D₂。

Compared with the prior art, the beneficial effects of the utility model are as follows:

the utility model discloses a head disk main part segmental arc, the turn that had both looked after gas just got into behind the impeller needs head disk turn radius as far as possible, looks after passage area between the blade gradually from little to big transition again for gas all has the obvious improvement of certain degree from flowing to the blade front end to the flow that gets into after the impeller, thereby has improved the acting efficiency and the performance parameter of impeller.

The utility model discloses mainly through increased straight induction zone at the impeller front bezel, improved because when the air current got into the impeller from the axial trun to radial, gas separation and the swirl that arouse. And, the straight inlet section is added at the inlet of the front disc, and the following functions are also realized:

1. the rigidity of the front disc is increased, and the inner ring of the front disc can bear the fatigue load caused by the long-term running of the impeller and is not easy to tear;

2. the roundness of the inlet ring is increased, and the radial clearance t between the air inlet and the impeller during assembly is better ensured₃The circumferential direction is uniform;

3. the roundness of the inlet ring is increased, and because the front disc forms a straight cylinder section when the die is used for drawing, profiling and processing, the contraction and resilience of the front disc are smaller, so that under the condition of assembling and welding the impeller, the positioning is more accurate from the process, and the jumping and dynamic balance of the impeller are better ensured, as shown in figure 1;

4. because the front disk is in a conical arc shape as a whole, when the air inlet and the impeller are assembled, the axial position of the air inlet and the impeller deviates to one side of the impeller, so that the radial fit clearance between the air inlet and the impeller is obviously increased, namely the internal leakage of the ventilator is obviously increased, and the pressure of the ventilator is obviously reduced. At present, because the annular inlet ring has a certain axial length s, when the axial position of the air inlet and the impeller during assembly is slightly deviated (particularly slightly deviated towards the inner side of the impeller), the radial clearance between the air inlet and the impeller is obviously increased, so that the leakage in the ventilator is increased, the outlet flow is reduced, the pressure is reduced and the power consumption is increased, as shown in fig. 2;

5. the addition of the flat inlet section means that the axial height of the front disk and the impeller is slightly increased, so that when the ventilator is assembled,compared with the straight section without the inlet, the axial installation position of the air inlet moves outwards by a distance s, and the distance t between the tail end of the air inlet and the front end of the blade₂And s is increased, so that the impeller inlet airflow is stabilized, and a better inlet airflow condition is provided for the blades to efficiently apply work to the air.

Drawings

FIG. 1 is a schematic view of the center positioning of the front plate during the assembly welding of the impeller of the present invention;

FIG. 2 is a diagram illustrating a prior art front plate inlet with an arc shape matching with an air inlet;

FIG. 3 is an assembly view of the ventilator of the present invention;

FIG. 4 is a view of the impeller structure of the ventilator of the present invention;

FIG. 5 is a schematic view of the inner side bus of the front plate of the impeller of the ventilator of the present invention;

FIG. 6 is a graph comparing the static pressures of example 2 and comparative sample 1;

FIG. 7 is a graph comparing the static pressure efficiency of example 2 with that of comparative sample 1;

FIG. 8 is a graph comparing the static pressures of example 3 and comparative sample 2;

fig. 9 is a graph comparing the static pressure efficiency of example 3 with that of comparative sample 2.

The reference numerals are explained below:

1. an impeller; 2. an air inlet; 3. a large disc; 4. a mandrel; 11. a rear disc; 12. a blade; 13. and a front disc.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

example 1

This example illustrates the effect of adding a straight inducer at the entrance of the front disc.

As shown in fig. 1, when the back plate 11, the blades 12 and the front plate 13 of the centrifugal impeller are assembled and welded, the center of the front plate is positioned by the vertical mandrel 4 and the large disc 3, wherein the mandrel is the axial center line of the impeller 1, the gap between the large disc and the inner wall of the inlet end of the front plate is delta, and the front plate is positioned in both the horizontal direction and the vertical direction. The front disc of the prior art, the circle is inhomogeneous because shrink deformation when the mould die mould is pressed in the front disc, has the ellipticity of certain degree, can entangle big disc for guaranteeing the minimum internal diameter of front disc, must turn the big disc external diameter car little, cause the uneven and front disc pitch arc of circumferential direction mass distribution of front disc and the laminating of blade pitch arc not tight of front disc, be connected with the deformation by force during the welding, it is big with initial dynamic unbalance amount to have to beat, must rely on the whole plastic of impeller to guarantee to beat and dynamic balance precision is qualified. Compared with the prior art, the utility model discloses a roundness of circle in the head disk is better, and the value of process gap delta can be littleer, and the possible degree in the skew impeller center in head disk center is littleer, can ensure that head disk central positioning is more accurate, and not only the head disk pitch arc is laminated with blade front end edge pitch arc more, and deformation during the welding is little, and the quality eccentric quantity of head disk and impeller part is littleer moreover, therefore beating of impeller is little, and the dynamic balance precision is high.

In addition, in the assembly of the air inlet 2 and the impeller 1, when the inlet of the front disk is an arc line in the prior art, due to errors caused in the assembly process, the depth of the air inlet sleeved into the front disk is slightly different, namely the axial overlapping is different, and a radial gap t between the air inlet and the front disk is caused₃Is significantly increased. As shown in fig. 2, when the inlet of the front disc is an arc, when the axial overlapping length of the air inlet and the front disc is 6mm, the radial gap between the air inlet and the front disc is 4.2 mm. When the air inlet axially extends into 8mm towards the front disc, the radial clearance between the air inlet and the front disc is 4.6mm, and the radial clearance is increased by 0.4 mm. At high impeller speeds, the 0.4mm clearance has a significant effect on airflow, which tends to increase leakage, decrease outlet flow, decrease pressure and increase power consumption in the fan.

In the application, the straight inlet section is added at the inlet of the front disc, and the straight inlet section has a certain axial length s, so that the axial position of the air inlet and the impeller during assembly is not slightly deviated, and particularly, when the straight inlet section slightly deviates towards the inner side of the impeller, the radial gap between the straight inlet section and the impeller is obviously increased. In the length range of the straight inlet section, the air inlet moves in the axial direction, and the radial clearance between the air inlet and the front disc is unchanged.

Further, as shown in FIG. 3, additional devices are providedThe straight inlet section means that the axial height of the front disc and the impeller is increased, so that when the ventilator is assembled, compared with the straight section without the inlet, the axial installation position of the air inlet moves outwards by a distance s, wherein s is the axial length of the straight inlet section and is equivalent to the distance t between the tail end of the air inlet and the front end of the blade₂And s is increased, so that the impeller inlet airflow is stabilized, and a better inlet airflow condition is provided for the blades to efficiently apply work to the air.

Example 2

This example illustrates the function of the arcuate section of the body.

The utility model discloses an embodiment 2 compares with comparison model machine 1, except that main part arc section cross-section pitch arc is different, all the other parts of its ventilation blower are the same completely, and the motor of adapted and operation rotational speed are also the same. Contrast 1 main part arc section cross sectional shape of model machine is the circular arc, and embodiment 2 main part arc section cross sectional shape does the utility model discloses a main part segmental arc curve, including straight induction zone "ab", main part segmental arc "bc", straight export section "cd" and export turn-ups section "def".

The relevant dimensions for example 2 and comparative sample 1 are as follows:

D₂=526.6 mm

D₀=352.5 mm

D₃=566 mm

s=6 mm

u=87 mm

v=53.5 mm

θ=31.6°

v/u=0.615

the performance curves of example 2 and comparative prototype 1 are compared in FIGS. 6-7; the comparison of the performance parameters of the working points with the same air volume is shown in the table 1.

TABLE 1

	Rotating speed (r/min)	Air volume (m)³/h）	Static pressure (Pa)	Static pressure efficiency (%)
					Comparative sample machine 1	1780	8424	851.6	66.5
Example 2	1780	8424	884.7	68.5

Under the working condition of the same air volume, compared with a comparative sample machine 1, the static pressure of the embodiment 2 is improved by 33.1Pa, and the static pressure efficiency is improved by 2%.

Example 3

This embodiment specifies the role of the arcuate section of the body by another impeller size.

The utility model discloses an embodiment 3 compares with comparison model machine 2, except that main part arc section cross-section pitch arc is different, all the other parts of its ventilation blower are the same completely, and the motor of adapted and operation rotational speed are also the same. Compare 2 main part arc section cross sectional shapes of model machine for the circular arc, embodiment 3's main part arc section cross sectional shape does the utility model discloses a main part arc section curve.

The relevant dimensions for example 3 and comparative sample 2 are as follows:

D₂=639.6 mm

D₀=444 mm

D₃=716 mm

s=7 mm

u=97.8 mm

v=68 mm

θ=34.8°

v/u=0.695

the performance curves of example 3 and comparative sample 2 are compared and shown in FIGS. 8-9; the comparison of the performance parameters of the working points with the same air volume is shown in the table 1.

TABLE 2

	Rotating speed (r/min)	Air volume (m)³/h）	Static pressure (Pa)	Static pressure efficiency (%)
					Comparative sample machine 2	1450	13230	845.4	70.2
Example 3	1450	13230	872.5	71.8

Under the working condition of the same air volume, the static pressure of the embodiment 3 is improved by 27.1Pa and the static pressure efficiency is improved by 1.6 percent compared with the comparison sample machine 2.

And (4) conclusion:

the utility model discloses an improvement scheme is mainly through the optimization of preceding dish cross-section camber line shape for blade front end inlet condition can improve in the impeller and the passageway between the blade in the flow field obtain optimizing, thereby improved the efficiency of impeller to the gas work, obviously improved the performance and the efficiency of ventilation blower, reduced energy consumption and noise, and impeller key feature size and technology processing mode do not have the change, have certain economy and social value.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the description of the above embodiments and the description is only for illustrating the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the present invention, and these changes and modifications fall within the scope of the present invention as claimed.

Claims

1. The utility model provides a centrifugal impeller, the impeller includes that head disk, back plate and even clamp are established a plurality of blades between head disk and the back plate, the space that adjacent blade and head disk, back plate enclose is the airflow channel in the impeller, and the air current is followed head disk axial gets into the impeller, through the runner between the blade after, flows from the impeller periphery, its characterized in that, head disk from airflow inlet to export, includes straight induction zone, main part segmental arc, straight export section and export turn-ups section in proper order, straight induction zone is straight tube-shape, and straight export section is the ring form, the entrance point of main part segmental arc with straight induction zone is tangent to be connected, the exit end of main part segmental arc with straight export section is tangent to be connected.

2. The centrifugal impeller of claim 1, wherein an inboard generatrix of the arcuate segment of the body is atThe following equations are satisfied in rectangular coordinates:

u is the radial width of main part segmental arc, and v is the axial height of main part segmental arc, crosses the axial parallel line that main part segmental arc exit end made the impeller obtains rectangular coordinate's x axle, crosses the radial parallel line that main part segmental arc entrance end made the impeller obtains rectangular coordinate's y axle, and wherein, x, y satisfy: x is more than or equal to 0 and less than or equal to v, and y is more than or equal to u and less than or equal to 0.

3. The centrifugal impeller according to claim 2, wherein the arc-shaped section of the main body of the front disk is inclined from the inner diameter to the outer diameter toward the rear disk side, and the angle of inclination of the front disk with respect to the plane of the rear disk is θ, θ =30 ° -40 °.

4. The centrifugal impeller as claimed in claim 2, wherein the ratio of the axial height of the arcuate section of the main body to the radial width of the arcuate section of the main body is 0.6 to 0.8.

5. A centrifugal impeller according to claim 1, wherein the axial length s of the flat inducer satisfies: s = (0.01 to 0.02) × D₂Wherein D is₂Is the outer diameter of the blade.

6. A ventilator, the ventilator includes the centrifugal impeller of claim 1-5, characterized by, also include the air intake, the impeller cover is established outside the air intake, the impeller with the axial overlap length t of air intake is₁，t₁Satisfies the following conditions: t is t₁=(0.01~0.02)×D₂。