JPH11294185A - Multistage compressor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multistage compressor structure capable of providing a high pressure-ratio by a simple constitution, and enlarging the degree of freedom in the design of the multistage compressor. SOLUTION: A multistage compressor is provided with an axial-flow stage 12 in which stationary blades 10 and moving blades 11 are arranged in multiple stages, a plurality of centrifugal compressors 22 arranged at equal intervals in the circumferential direction and rotatably connected to the compressor main shaft 6 vial a bevel gear 21 at the rear part of the axial-flow stage 12 of the multistage compressor for pressurizing the air taken from the front toward the rear by rotating the moving blades 11 by the compressor main shaft 6, and a distributing duct 24 for distributedly supplying the compressed air from the axial-flow stage 12 to the suction scrolls 23 of the respective centrifugal compressors 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage compressor structure.

[0002]

2. Description of the Related Art A conventional multi-stage compressor A for a gas turbine.
As shown in FIG. 4, inside the casing 1 (left end in FIG. 4), a required annular space 8
The fixing member 2 is fixed by a strut 3 so as to hold the fixing member, and the fixing member 4 is fixed by a strut 5 inside the rear of the casing 1 (the right end in FIG. 4). 4, the casing 1
A compressor main shaft 6 (output shaft) concentric with the shaft 7 is rotatably provided by a bearing 7.

[0003] To the compressor main shaft 6 is fixed a moving blade mounting cylinder 9 formed such that the annular space 8 is narrowed rearward from the fixing member 2.

[0004] On the inner surface of the casing 1, a stationary blade 10 extending in the annular space 8 and approaching the outer surface of the moving blade mounting barrel 9 is provided.
A plurality of stages are provided at required intervals from the front to the rear, and furthermore, a moving blade 11 located on the rear side of each of the stationary blades 10 and extending close to the inner surface of the casing 1 is provided with the moving blade attachment. It is fixed to the cylinder 9, which forms an axial flow stage 12. Each of the stationary blade 10 and the moving blade 11 gradually decreases in length from the front to the rear.

[0005] Behind the axial flow stage 12, a casing 1 is provided by vanes 13, 14 provided at a required interval.
Is provided, and a combustor 16 is provided between the inner member 15 and the casing 1.

Further, between the stationary blade 14 behind the combustor 16 and the strut 5, a turbine rotor blade fixing member 1 is provided.
A turbine rotor blade 18 is fixed to the compressor main shaft 6 via the rotor 7 to form a turbine 19.

In the multi-stage compressor A shown in FIG. 4, air taken in from the front is sequentially compressed by multi-stage compression by an axial flow stage 12 composed of a moving blade 11 and a stationary blade 10 rotated by the rotation of the compressor main shaft 6. The compressed air having the increased pressure is guided to the combustor 16 to become a high-temperature and high-pressure fluid by fuel combustion and guided to the turbine 19, thereby rotating the turbine blade 18 and thereby the compressor. The main shaft 6 is driven to rotate.

In the multistage compressor A shown in FIG. 4, in order to achieve a high pressure ratio, an axial flow stage 12 in which the number of stages of the stationary blade 10 and the moving blade 11 is increased is performed.

Further, as a conventional multi-stage compressor A designed to increase the pressure ratio, one having a structure as shown in FIG. 5 is also employed.

That is, the multi-stage compressor A shown in FIG. 5 has a swan-neck shape in which the diameter of the inlet of the impeller 29 is reduced behind the axial flow stage 12 similar to FIG. A centrifugal compressor 20 is provided so as to face outward, and compressed air passing through a diffuser 30 and outlet guide vanes 31 is guided to a combustor 16 extending in a lateral direction. In FIG. 5, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description is omitted.

In the multi-stage compressor A shown in FIG. 5, air taken in from the front is sequentially compressed by multi-stage compression by an axial flow stage 12 composed of a moving blade 11 and a stationary blade 10 rotating by the rotation of the compressor main shaft 6. The pressure of the compressed air, which has been increased to a high pressure, is further increased by the centrifugal compressor 20 and then guided to the combustor 16 to become a high-temperature and high-pressure fluid by combustion of the fuel and to be guided to the turbine 19. .

[0012]

However, in the conventional multi-stage compressor A shown in FIG. 4, if the number of stages of the axial flow stage 12 is increased in order to achieve a high pressure ratio, the number of parts increases. On the other hand, the pressure ratio per stage cannot be increased, and the loss due to clearance leakage increases due to the reduced blade height. Therefore, at a certain number of stages or more, a high pressure ratio cannot be expected without lowering the efficiency level. Had.

In the multi-stage compressor A shown in FIG. 5, the outer diameter of the impeller 29 of the centrifugal compressor 20 cannot be made large because of the high temperature. In addition, the fluid already compressed in the axial flow stage 12 and having a reduced volume flows in, so that the blade height of the impeller 29 is reduced, the loss due to clearance leakage increases, and the flow path height is reduced. There is a problem that friction loss increases and a large increase in pressure ratio cannot be expected without lowering the efficiency level.

Further, by adding the centrifugal compressor 20 coaxially with the axial flow stage 12 as described above, the degree of freedom of design is restricted, and the centrifugal compressor 20 is designed in an optimum parameter range. Had the problem that it was difficult.

The present invention has been made to solve the above-mentioned conventional problems. A multi-stage compressor which can obtain a high pressure ratio with a simple structure and greatly expands the design freedom of the multi-stage compressor A can be obtained. It is intended to provide structure.

[0016]

SUMMARY OF THE INVENTION The present invention provides an axial flow stage in which a stationary blade and a moving blade are arranged in multiple stages, and the air taken in from the front is rotated by rotating the moving blade around a compressor main shaft. At the rear of the axial flow stage of the multi-stage compressor which is adapted to pressurize, a centrifugal compressor connected to the compressor main shaft so as to be driven to rotate via a bevel gear is equidistant in the circumferential direction. And a distribution duct for supplying compressed air from the axial flow stage to the intake scroll of each of the centrifugal compressors is provided.

In the present invention, a plurality of centrifugal compressors are provided at the rear of the axial flow stage so as to transmit the rotation of the compressor main shaft to the impeller via bevel gears. A distribution duct for distribution to the intake scroll of the machine is provided, so the number of rotations of the impeller can be arbitrarily increased by selecting the gear ratio of the bevel gear, and the capacity can be increased by selecting the number of centrifugal compressors installed. It can be arbitrarily changed, so that a high pressure ratio can be obtained with a simple configuration, and the degree of freedom in aerodynamic design can be greatly improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a multi-stage compressor structure according to the present invention. The multi-stage compressor has an axial flow stage 12 in which a stationary blade 10 and a moving blade 11 are arranged in multiple stages. At the rear of said axial stage 12 of the multi-stage compressor being rotated by 6;
A centrifugal compressor 22 connected to the compressor main shaft 6 via a bevel gear 21 so as to be driven to rotate is provided. 21a is a gear provided on the compressor main shaft 6 and meshed with the bevel gear 21.

A plurality of centrifugal compressors 22 are provided at equal intervals in the circumferential direction of the compressor main shaft 6. FIG. 1 shows one centrifugal compressor 22.

Further, at the rear end of the axial flow stage 12, there is provided a distribution duct 24 for distributing and supplying the compressed air from the axial flow stage 12 to the intake scrolls 23 of the centrifugal compressors 22.
Is provided.

As shown in FIGS. 2 and 3, the centrifugal compressor 22 has a configuration similar to that of a centrifugal compressor rotor for a turbocharger. Bevel gear 2
The compressed air from the centrifugal compressor 22 is compressed by an impeller 26 provided integrally with the first shaft 25 and discharged from a circumferential scroll 27 to a discharge portion 28. The compressed air shown in FIG. It is supplied to the combustor 16.

The operation of the multi-stage compressor A shown in FIGS. 1 to 3 will be described below.

The compressed air compressed by the axial flow stage 12 is supplied to a plurality of centrifugal compressors 2 provided by distribution ducts 24.
And distributed to the second intake scroll 23.

Each centrifugal compressor 22 is compressed by an impeller 26 rotating via a gear 21 a and a bevel gear 21 by rotation of the compressor main shaft 6, and supplied to the combustor 16 from a discharge portion via a scroll 27.

At this time, a plurality of centrifugal compressors 22 for transmitting the rotation of the compressor main shaft 6 to the impeller 26 via the bevel gear 21 are provided at the rear of the axial flow stage 12, so that the gears 21 are provided.
By selecting the gear ratio between a and the bevel gear 21, the number of revolutions of the impeller 26 can be arbitrarily increased, and the capacity can be arbitrarily changed by selecting the number of centrifugal compressors 22 to be installed. A high pressure ratio can be obtained with a simple configuration, and the degree of freedom in aerodynamic design can be greatly improved.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0028]

As described above, according to the present invention, a plurality of centrifugal compressors for transmitting the rotation of the compressor main shaft to the impeller via bevel gears are provided at the rear of the axial flow stage. A distribution duct that distributes the compressed air from the stage to the intake scroll of each centrifugal compressor is provided, so the rotation speed of the impeller can be arbitrarily increased by selecting the gear ratio of the bevel gear, and the centrifugal compressor can be further increased. The capacity can be arbitrarily changed by selecting the number of installations, so that a high pressure ratio can be obtained with a simple configuration, and the degree of freedom in aerodynamic design can be greatly improved. The effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cut-away side view showing an example of a multi-stage compressor structure of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is an external side view of the centrifugal compressor of FIG.

FIG. 4 is a partially cut-away side view showing an example of a conventional multi-stage compressor structure.

FIG. 5 is a partially cut-away side view showing another example of a conventional multi-stage compressor structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Stator blade 11 Moving blade 12 Axial flow stage 21 Bevel gear 22 Centrifugal compressor 23 Intake scroll 24 Distribution duct

Claims (1)

[Claims] An airflow stage in which a stationary blade and a moving blade are arranged in multiple stages is provided, and the air taken in from the front is pressurized rearward by rotating the moving blade on a compressor main shaft. At the rear of the axial stage of the multistage compressor, a plurality of centrifugal compressors connected to the main shaft of the compressor so as to be driven to rotate via bevel gears are provided at equal intervals in the circumferential direction, and the axial flow is provided. A multi-stage compressor structure comprising a distribution duct for supplying compressed air from a stage to intake scrolls of the centrifugal compressors.