CN100462566C

CN100462566C - Big and small impeller vane impeller with non-homogeneously distributed blades along circumference and compressor machine

Info

Publication number: CN100462566C
Application number: CNB2007101784035A
Authority: CN
Inventors: 刘火星; 王洪伟; 严明; 陈懋章; 蒋浩康; 田网南; 李家云; 何勇
Original assignee: Beihang University
Current assignee: Changzhou Lanxiang Machinery Works; Beihang University
Priority date: 2007-11-29
Filing date: 2007-11-29
Publication date: 2009-02-18
Anticipated expiration: 2027-11-29
Also published as: CN101173673A

Abstract

The invention discloses a compressor and an impeller with big and small blades unevenly distributed along circumferential direction; wherein, the big blade of the impeller with big and small blades is unevenly distributed along circumferential direction, and the variation value of the distance in circumferential direction is equal to or less than ten percents. The invention is characterized in that: a small blade is arranged between the adjacent two big blades; the distance in circumferential direction between the small blade and the big blade near the side of the pressure surface of the small blade is equal to twenty-five percents to seventy percents of the distance in circumferential direction between the adjacent big blades. The invention has the advantages that when the rotor of the compressor is the impeller with big and small blades, the exciting force imposed on the downstream stator by the wake of the rotor blade is not periodical strictly, and the destructive influence of the downstream stator is less.

Description

Blade is along the big and small blade impeller and the gas compressor of circumferential non-uniform Distribution

Technical field

The present invention relates to a kind of blade impellers and mechanical device, relate in particular to a kind of big and small blade impeller and gas compressor.

Background technique

Vane compressor generally is used for to gas boosting, is divided into axial flow, centrifugal and diagonal flow type gas compressor.Axial-flow compressor gas flow mode is axial admission, axial exhaust; Centrifugal-flow compressor gas flow mode is an axial admission, radially exhaust; The diagonal flow type gas compressor is the compromise of axial flow and centrifugal compressor, and axial admission and axially has the several angle exhaust.Axial flow and diagonal flow type gas compressor comprise impeller, comprise rotor and stator, and impeller is provided with blade.The structural type of blade is very big to the boosting capability influence of gas compressor.

During the compressor rotor blade rotation, the tail that air flow stream is crossed generation is beaten the Ye Paishang at the downstream stator, can produce periodically excitation force, if the own natural frequency of this excitation force and stator is close, can produce resonance and destroy stator blade, or influence the stator blade life-span because of high cycle fatigue.The common feature of conventional axial flow compressor is to adopt the identical blade of size evenly to distribute along circumferential direction, and the passage that forms between blade and the blade is identical.

As shown in Figure 1, gas compressor of the prior art, the distribution mode of blade 1 all is along circumferentially equally distributed in the rotor.

There is following shortcoming at least in above-mentioned prior art:

Because rotor blade is circumferentially equally distributed, the excitation force that its tail produces the downstream stator blade also is strict periodic, when rotating speed and number of rotor blades satisfy when necessarily concerning, the frequency of this excitation force may be mutually close with the natural frequency of vibration of downstream stator blade, thereby cause that resonance causes accident.Even do not resonate, long this periodicity exciting also can make stator blade crack because of the High Cycle Fatigue problem, shortens gas compressor working life greatly.

Summary of the invention

The purpose of this invention is to provide a kind of big and small blade impeller and gas compressor to the less circumferential non-uniform Distribution in blade edge of the damaging influence of downstream stator.

The objective of the invention is to be achieved through the following technical solutions:

Blade of the present invention comprises a plurality of big blades along the big and small blade impeller of circumferential non-uniform Distribution, it is characterized in that, described a plurality of big blades are along circumferential non-uniform Distribution.

Gas compressor of the present invention, the rotor of this gas compressor are above-mentioned blade along the circumferential big and small blade impeller of non-uniform Distribution.

As seen from the above technical solution provided by the invention, blade of the present invention is along the big and small blade impeller and the gas compressor of circumferential non-uniform Distribution, because a plurality of big blade of big and small blade impeller is along circumferential non-uniform Distribution, when compressor rotor adopts this vane collocation form, the rotor blade tail is strict periodic to the excitation force right and wrong that the downstream stator blade produces, and is less to the damaging influence of downstream stator.

Description of drawings

Fig. 1 is the blade distribution schematic diagram of impeller of the prior art;

Fig. 2 is the blade distribution schematic diagram of blade of the present invention along the big and small blade impeller of circumferential non-uniform Distribution;

Fig. 3 is the schematic representation that concerns of the position of small leaf among the present invention and rotor efficiency;

The downstream pressure pulsation time-domain diagram that Fig. 4 causes for compressor rotor blade wake passing in the prior art;

The downstream pressure pulsation frequency domain figure that Fig. 5 causes for compressor rotor blade wake passing in the prior art;

The downstream pressure pulsation time-domain diagram that Fig. 6 causes for compressor rotor blade wake passing among the present invention;

The downstream pressure pulsation frequency domain figure that Fig. 7 causes for compressor rotor blade wake passing among the present invention.

Embodiment

Blade of the present invention is along the big and small blade impeller of circumferential non-uniform Distribution, and its preferable embodiment comprises a plurality of

big blades

2,3,4 as shown in Figure 2, the circumferential non-uniform Distribution in edge between a plurality of

big blades

2,3,4.

In a plurality of

big blades

2,3,4, the distance of the circumferential direction between adjacent two

big blades

2,3 is that width is from S2; Distance between adjacent two

big blades

3,4 is narrow apart from S1.Can be width from S2 and narrowly distribute along the distribution of the big blade in one week of big and small blade impeller apart from the S1 space.It also can be other non-uniform Distribution mode.

Width can be smaller or equal to 10% from S2 and narrow changing value apart from S1.

In a plurality of

big blades

2,3,4, can be provided with small leaf between adjacent two big blades.As being provided with first small leaf 5 between first blade 2 and the second largest blade 3; Be provided with accessory flocculus sheet 6 between second largest blade 3 and the third-largest blade 4.

Small leaf

5,6 is apart from the circumferential distance of the big blade of its pressure side one side, and promptly first small leaf 5 equals 25%-70% of adjacent first blade 2 and the circumferential distance S1 between the second largest blade 3 apart from the circumferential distance S21 of the second largest blade 3 of its pressure side one side; Equally, accessory flocculus sheet 6 equals 25%-70% of adjacent second largest blade 3 and the circumferential distance S1 between the third-largest blade 4 apart from the circumferential distance S11 of the third-largest blade 4 of its pressure side one side.

That is, 25%＜S11/S1＜70% and 25%＜S21/S2＜70%, preferred 40%＜S11/S1＜60% and 40%＜S21/S2＜60% can be 25%, 30%, 40%, 50%, 60%, 70% etc.

Among the present invention, the circumferential position of the epitrochanterian big blade of gas compressor is not equally distributed, can change according to the requirement of frequency.The tail of the big blade of rotor is not a single-frequency to the main excitation force of downstream stator blade like this, but certain dispersed distribution is arranged, and has weakened the influence to stator blade.

The relative variation maximum value of big tangential blade space can be no more than 10%, changes little to the influence of aeroperformance in this scope.During design, uneven distribution will satisfy wheel disc in the symmetry properties that makes progress in week, in order to avoid produce unbalanced force.

On the basis of big blade uneven distribution, the circumferential distribution that is positioned at small leaf wherein will be satisfied two principle: one is the balance that will guarantee wheel disc, and another is to carry out aerodynamic optimization to each different blade path respectively, to obtain best performance.

As shown in Figure 3, when the circumferential position P of small leaf (ratios of two big blade pitghs that small leaf is adjacent apart from the circumferential distance of the big blade of its pressure side one side) is between 25%～70%, very little to the rotor performance influence.

As Fig. 4, shown in Figure 5, in the prior art, the pressure pulsation power that the circumferential equally distributed rotor of blade produces the downstream is in the frequency set.

As Fig. 6, shown in Figure 7, among the present invention, the pressure pulsation power that the rotor of the circumferential non-uniform Distribution of blade produces the downstream, frequency dispersion, can partly solve the problem that stator blade is concentrated because of the upstream excitation force frequency, the resonance of effectively placing stator blade destroys, and is also beneficial to the fatigue life of stator blade.

In addition, small leaf does not wait in circumferential distance apart from adjacent two big blades, can more effectively control the separation at leaf grating rear portion.The circumferential position P value of small leaf can be different at the different radii place, can be optimized in pneumatic design, obtain best aeroperformance, and qualified through the intensity verification.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.

Claims

1. a blade is along the circumferential big and small blade impeller of non-uniform Distribution, comprise a plurality of big blades, it is characterized in that, described a plurality of big blade is along circumferential non-uniform Distribution, in described a plurality of big blade, the distance of the circumferential direction between adjacent two big blades comprise width from narrow distance, described width is from distributing apart from the space with narrow.

2. blade according to claim 1 is characterized in that along the big and small blade impeller of circumferential non-uniform Distribution the changing value of the circumferential distance between described adjacent two big blades is smaller or equal to 10%.

3. blade according to claim 1 and 2 is characterized in that along the big and small blade impeller of circumferential non-uniform Distribution, in described a plurality of big blades, is provided with small leaf between adjacent two big blades.

4. blade according to claim 3 is characterized in that along the circumferential big and small blade impeller of non-uniform Distribution, described small leaf apart from the circumferential distance of the big blade of its pressure side one side equal between adjacent two big blades circumferential distance 25%-70%.

5. blade according to claim 4 is characterized in that along the circumferential big and small blade impeller of non-uniform Distribution, described small leaf apart from the circumferential distance of the big blade of its pressure side one side equal between adjacent two big blades circumferential distance 40%-60%.

6. a gas compressor is characterized in that, the rotor of this gas compressor is the big and small blade impeller of each described blade of claim 1 to 5 along circumferential non-uniform Distribution.