CN209959567U

CN209959567U - Series cascade diffuser of centrifugal compressor

Info

Publication number: CN209959567U
Application number: CN201920338792.1U
Authority: CN
Inventors: 房骏翌; 齐永春; 孟亮
Original assignee: Liaoning Fuan Gas Turbine Co Ltd
Current assignee: Liaoning Fuan Gas Turbine Co Ltd
Priority date: 2019-03-18
Filing date: 2019-03-18
Publication date: 2020-01-17
Anticipated expiration: 2029-03-18

Abstract

The utility model relates to a centrifugal compressor tandem cascade diffuser, diffuser include preceding baffle, back baffle, arc blade, are equipped with outer lane blade, inner circle blade between preceding baffle, the back baffle, and the inner circle blade corresponds position between two adjacent outer lane blades, and arc blade is the arc rectangular piece, and arc rectangular piece both sides are equipped with preceding base, back base respectively, and preceding base, back base thickness are greater than the arc rectangular piece, preceding base and preceding baffle welding, back base and back baffle welding. Through the components of a whole that can function independently of inner circle blade, outer lane blade arrange, solved the restriction of traditional single-row blade diffuser in the aspect of aspect ratio for the diffuser has bigger diameter, and can not cause the separation of the inside air current of diffuser, improves the aerodynamic efficiency and total pressure recovery coefficient of major diameter diffuser.

Description

Series cascade diffuser of centrifugal compressor

Technical Field

The utility model relates to a centrifugal compressor device technical field, concretely relates to centrifugal compressor tandem cascade diffuser.

Background

In the field of rotating machinery, particularly in compressors, the design of diffusers has a significant impact on the overall performance of the compressor. Conventional diffusers are classified into vaneless diffusers and vane diffusers, which are classified into airfoil diffusers, wedge diffusers, and the like. The common airfoil diffuser is generally limited by factors such as aspect ratio, whole machine size and the like, and under the condition of overlarge radial size, airflow cannot be well guided, so that the separation phenomenon is generated at the downstream in the diffuser, meanwhile, the secondary flow disturbance can penetrate through the whole diffuser under the influence of the blade top gap flow of the impeller, and therefore, the design of the novel diffuser suitable for the environment with large chord length is very necessary.

Disclosure of Invention

An object of the utility model is to solve above-mentioned problem, provide a centrifugal compressor tandem cascade diffuser, it is applicable to the major diameter diffuser, and performance is good.

In order to solve the above problem, the utility model discloses a technical scheme as follows:

a serial cascade diffuser of a centrifugal compressor is characterized by comprising a front partition plate, a rear partition plate and arc-shaped blades, wherein the front partition plate and the rear partition plate are annular, each arc-shaped blade comprises an outer ring blade and an inner ring blade, the front partition plate and the rear partition plate are respectively provided with an outer ring blade fixing hole and an inner ring blade fixing hole, the outer ring blade and the inner ring blade are arranged between the front partition plate and the rear partition plate and respectively correspond to the outer ring blade fixing hole and the inner ring blade fixing hole, the outer ring blades and the inner ring blades are uniformly distributed in a circumferential mode side by side, the inner ring blades correspond to the positions between two adjacent outer ring blades, an inner ring blade inlet is formed between the adjacent inner ring blades at the central hole of the diffuser, an outer ring blade outlet is formed between the adjacent outer ring blades at the outer side of the diffuser, the arc-shaped blades are arc-, the thickness of the front base and the rear base is larger than that of the arc-shaped long sheet, the front base is welded with the front partition plate, and the rear base is welded with the rear partition plate.

In the cascade diffuser of the centrifugal compressor, the outlet angle alpha of the blades of the inner ring₂Angle alpha with respect to the inlet of the outer ring blade₃The difference between the two satisfies within 6 degrees, and the inlet angle alpha of the inner ring blade₁The outlet angle of the outer ring blade is consistent with the outlet airflow angle of the impeller₄Depending on the component to which the diffuser rear is connected.

According to the tandem cascade diffuser of the centrifugal compressor, the root parts of the arc long pieces of the arc blades, which are connected with the front base and the rear base, are rounded corners and fillets.

Compared with the prior art, the utility model discloses favourable effect does:

1. the inner ring blades and the outer ring blades are arranged in a split manner, so that the limitation of the traditional single-row blade diffuser in the aspect of aspect ratio is solved, the diffuser is larger in diameter, the separation of air flow in the diffuser cannot be caused, and the pneumatic efficiency and the total pressure recovery coefficient of the large-diameter diffuser are improved;

2. the root parts of the arc-shaped long pieces, which are connected with the front base and the rear base, are all rounded, so that the problem of stress concentration at the root parts of the diffuser blades with smaller thickness is effectively solved, meanwhile, the cross sections of the passages of the diffuser blades can be smooth, the influence of vortex at the sharp corners of the passages is weakened, the influence of secondary flow in the direction of the front partition plate is greatly weakened, and the overall efficiency of the gas compressor is improved;

3. inner ring blade exit angle alpha₂Angle alpha with respect to the inlet of the outer ring blade₃Satisfy alpha₂-α₃Less than or equal to 6 degrees, the wake gap flow of the inner ring blade has a blowing effect on the boundary layer of the outer ring blade, the pneumatic performance of the outer ring blade is improved, and the total pressure recovery coefficient of the diffuser is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a general structure diagram of a serial cascade diffuser of a centrifugal compressor according to the present invention;

fig. 2 is a layout diagram of the arc-shaped blades of the present invention;

FIG. 3 shows the inlet angle α of the inner ring blade of the present invention₁Inner ring blade exit angle alpha₂Outer ring blade inlet angle alpha₃Outer ringBlade exit angle alpha₄A distribution diagram;

FIG. 4 is a perspective view of the arc-shaped blade of the present invention;

FIG. 5 is a front view of the curved blade of the present invention;

description of reference numerals: the blade comprises a front partition plate-1, a rear partition plate-2, arc-shaped blades-3, outer ring blades-31, inner ring blades-32, arc-shaped long blades-33, a front base-34, a rear base-35, outer ring blade fixing holes-41, inner ring blade fixing holes-42, inner ring blade inlets-5 and outer ring blade outlets-6.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention can be more clearly and clearly defined.

A tandem cascade diffuser of a centrifugal compressor is characterized by comprising a front partition plate 1, a rear partition plate 2 and arc-shaped blades 3, wherein the front partition plate 1 and the rear partition plate 2 are annular, each arc-shaped blade comprises an outer-ring blade 31 and an inner-ring blade 32, the front partition plate 1 and the rear partition plate 2 are respectively provided with an outer-ring blade fixing hole 41 and an inner-ring blade fixing hole 42, an outer-ring blade 31 and an inner-ring blade 32 are arranged between the front partition plate 1 and the rear partition plate 2, the outer-ring blade 31 and the inner-ring blade 32 respectively correspond to the outer-ring blade fixing hole 41 and the inner-ring blade fixing hole 42, the outer-ring blades 31 and the inner-ring blades 32 are uniformly distributed in a circumferential direction side by side, the inner-ring blades 32 correspond to the position between two adjacent outer-ring blades 31, an inner-ring blade inlet 5 is formed between the adjacent inner-ring blades at the center hole of the, the both sides of the arc-shaped long sheet are respectively provided with a front base 34 and a rear base 35, the thicknesses of the front base 34 and the rear base 35 are larger than that of the arc-shaped long sheet 33, the front base 34 is welded with the front partition board 1, and the rear base 35 is welded with the rear partition board 2.

The front part of the diffuser is connected with an impeller, the impeller corresponds to an air inlet of the diffuser, and the rear part of the diffuser is connected with an annular channel, a reflux device or a volute gas collection chamber. Inner ring blade exit angle alpha₂Angle alpha with respect to the inlet of the outer ring blade₃The difference between the two is controlled within 6 degrees; inner ring blade inlet angle alpha₁The airflow angle at the outlet of the impeller is consistent with that at the outlet of the impeller, the airflow angle at the outlet of the impeller depends on the rotating speed of the impeller and the blades of the impeller, and the airflow angle at the outlet of the impeller is determined for the impeller rotating at a fixed speed; outer ring blade exit angle alpha₄Outer ring blade exit angle alpha depending on the component to which the diffuser aft is connected₄With no flow separation occurring, the outer ring blade exit angle alpha being defined when the diffuser is followed by a radial annular passage₄90 ~ 95 degree, and taking the outlet angle alpha of the outer ring blade when the diffuser is connected with the back of the flow returning device or the volute collection chamber₄Angle alpha with respect to the inlet of the outer ring blade₃The difference is 12 deg. ~ 20 deg..

The root parts of the arc-shaped long pieces 33 of the arc-shaped blades, which are connected with the front base 34 and the rear base 35, are fillets, the radius R of each fillet is 1 ~ 5mm, the arc-shaped blades which are processed independently are inserted into outer ring blade fixing holes and inner ring blade fixing holes of the front partition plate one by one, the root parts of the fillets are flush with the surface of the front partition plate and then are welded and fixed, the outer ring blade fixing holes and the inner ring blade fixing holes of the rear partition plate are inserted into the installed diffuser blades correspondingly, and the bottoms of the fillets are flush with the surface of the rear partition plate and then are welded.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred embodiments of the present invention, and the present invention is not limited by the above preferred embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention, and these changes and modifications all fall into the scope of the present invention as claimed.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A serial cascade diffuser of a centrifugal compressor is characterized by comprising a front partition plate (1), a rear partition plate (2) and arc-shaped blades (3), wherein the front partition plate (1) and the rear partition plate (2) are annular, each arc-shaped blade comprises an outer ring blade (31) and an inner ring blade (32), outer ring blade fixing holes (41) and inner ring blade fixing holes (42) are formed in the front partition plate (1) and the rear partition plate (2), the outer ring blades (31) and the inner ring blades (32) are arranged between the front partition plate (1) and the rear partition plate (2), the outer ring blades (31) and the inner ring blades (32) respectively correspond to the outer ring blade fixing holes (41) and the inner ring blade fixing holes (42), a plurality of outer ring blades (31) and inner ring blades (32) are uniformly distributed in parallel and circumferentially, the inner ring blades (32) correspond to the position between two adjacent outer ring blades (31), and an inner ring blade inlet (5) is formed between, outer ring blade export (6) are formed between adjacent outer ring blades in the diffuser outside, arc blade (3) are arc long piece (33), and arc long piece both sides are equipped with preceding base (34), back base (35) respectively, and preceding base (34), back base (35) thickness are greater than arc long piece (33), and preceding base (34) and preceding baffle (1) welding, back base (35) and back baffle (2) welding.

2. The tandem cascade diffuser of a centrifugal compressor as recited in claim 1 wherein the inner ring blade exit angle α₂Angle alpha with respect to the inlet of the outer ring blade₃The difference between the two satisfies within 6 degrees, and the inlet angle alpha of the inner ring blade₁The outlet angle of the outer ring blade is consistent with the outlet airflow angle of the impeller₄Depending on the component to which the diffuser rear is connected.

3. The tandem cascade diffuser of the centrifugal compressor according to claim 1, wherein the root parts of the arc-shaped long blades (33) of the arc-shaped blades, which are connected with the front base (34) and the rear base (35), are rounded.