JP2014218940A - Stator structure of axial flow compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable compressed air by reducing the size of a gap formed on a part to which an end surface in a radial direction of a stator of a stationary blade variable type axial flow compressor faces, and blocking an unexpected flow channel of compressed air.SOLUTION: An inside surface 10a of a stator casing 10, inside and outside surfaces 11a, 11b of a stator 11 and an outside surface 13a of a support ring 13 are formed by a concentric cylindrical surface with an output shaft 4 as a center. Consequently, the inside surface 10a of the stator casing 10 and the outside surface 11a of the stator 11 can make close to each other as much as possible, and the inside surface 11b of the stator 11 and the outside surface 13a of the support ring 13 can also make close to each other as much as possible, and thereby, a gap between these opposite surfaces is reduced as much as possible, and an unexpected flow channel of compressed air is blocked.

Description

  The present invention relates to a structure of a stator of an axial flow compressor used in, for example, a gas turbine.

  A gas turbine compresses a large amount of air sucked from a suction port with a compressor to generate high-pressure air, injects fuel and burns it together with the high-pressure air, and rotates the turbine with the generated high-temperature and high-pressure air to generate power. It is a device to take out. Further, there is a jet engine as a device that obtains propulsive force by ejecting exhaust gas from a turbine instead of obtaining rotational force.

  Among the compressors, an axial compressor compresses gradually while flowing in sucked air to generate high-pressure air. A stator (stator vane) is arranged in parallel in the axial direction at an appropriate interval with the inside facing a cylindrical stator casing. A rotor shaft is rotatably supported at the center, and a rotor (moving blade) is disposed on the rotor shaft at a position between the stators. That is, a stage composed of a rotor and a stator is arranged in parallel in a plurality of stages in the axial direction, air is pressurized by a rotor that rotates by the rotation of the rotor shaft, and the direction of the airflow is changed by a stator that does not rotate. Air is pressurized while guiding to the stage. The stator includes a stationary blade variable type that is rotatably supported around a radial axis, and a stationary blade fixed type that does not rotate.

  FIG. 2 is a cross-sectional view taken along the axial direction for explaining the schematic structure of the axial-flow compressor 1. An appropriately shaped stator 2a is juxtaposed at an appropriate interval in a cylindrical stator casing 2. A rotor shaft 4 is disposed so as to be rotatable about the output shaft 3, and a rotor 4 a attached to the rotor shaft 4 and turning by the rotation of the rotor shaft 4 is disposed at a position between the stators 2 a. . As shown in FIG. 2, the interval between the stators 2a is gradually narrowed, and the thickness of the rotor 4a disposed between them is gradually reduced.

  FIG. 3 is a front view of the stator 2a. In the stator 2a, a plurality of stators 2a are arranged in the circumferential direction of a circle with the rotor shaft 4 as the center. The stator 2a has an outer peripheral side supported by the stator casing 2 by an outer shaft 2c, and an inner peripheral side supported by a support ring 2e by an inner shaft 2d. The stator 2a is attached by the outer shaft 2c and the inner shaft 2d so as to be rotatable about the radial direction of the shaft of the stator casing 2.

  As shown in FIG. 2, an air suction port 5 is provided at the end of the stator casing 2, and the air sucked from the air suction port 5 is compressed by the rotation of the rotor 4a and the stator. The airflow is guided to the rotor 4a in the subsequent stage by 2a, and the pressure is gradually increased, and sufficiently compressed high-pressure air is supplied to a combustion section (not shown) following the axial flow compressor 1. .

  As a stator blade shape of the axial compressor described above, Patent Document 1 discloses a stator blade device shape for an axial compressor that minimizes an error or deviation in the angular position of the stator blade. Further, in Patent Document 2, each stationary blade constituting the blade row is supported so as to be swingable around an axial center extending in the radial direction, and a flexible seal member is provided at a blade end portion of each stationary blade. A shaft in which the seal member is formed of a heat-resistant rubber member with a thick end and a thin tip, with one end fixed to the blade tip and the other end sliding while contacting the wall that supports the stationary blade A variable stator vane mechanism for a flow compressor is disclosed. Further, in the stationary vane shape of the axial flow type air compressor, the axial flow type air compressor is arranged such that the tip is opposed to the outer surface of the rotor drum that is coaxially supported in the compressor casing with a gap. An axial-flow type air compressor in which the position of the stacking shaft extending in the rearward direction of the compressor and passing through the portion where the cross sections of the stationary blades overlap from the proximal end to the distal end of the stationary blade is set near the front end of the stationary blade (See Patent Document 3)

JP-A 64-12035 JP 2000-345997 A Utility Model Registration No. 2602142

  In the stator vane variable type stator 2a, the opening angle between the front and rear stages is adjusted by changing the angle by rotating about the radial direction passing through the outer shaft 2c and the inner shaft 2d, and the flow of compressed air Is guided to the rotor 4 at the subsequent stage. When the state of the compressed air guided by the stator 2a is not appropriate, the pressure, flow rate, etc. of the high-pressure air generated by the axial compressor does not become a desired state, and the subsequent combustion unit or turbine A desired output cannot be obtained, and as a result, a desired output as a gas turbine cannot be obtained.

  In particular, in the stationary blade variable axial compressor, the stator 2a is rotatably supported by the outer shaft 2c and the inner shaft 2d, so that the outer surface of the stator 2a and the inner surface of the stator casing 2 are A gap is formed between the inner surface of the stator 2a and the outer surface of the support ring 2e. Since the compressed air also flows to the subsequent stage from this gap, the state of the compressed air depends on the change in the gap. For example, the variable stator blade mechanism described in Patent Document 2 employs a structure in which the gap is closed with a seal member.

  By the way, in the conventional stator vane variable stator 2a, as shown in FIG. 3, both the outer and inner surfaces of the stator 2a are processed into a flat shape. For this reason, it is inevitable that a gap is formed between the outer side and the inner side of the stator 2a, and the compressed air may flow from the gap to the subsequent stage, and the compressed air may not be raised to a desired pressure. .

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stator structure of an axial compressor that can minimize the gap between the inner and outer surfaces of the stator vane variable type stator and the stator casing and the support ring. Yes.

  As a technical means for achieving the above object, a stator structure of an axial compressor according to the present invention is supported by a stator casing and a support ring on a radial support shaft centering on an output shaft, and the support In the axial flow compressor having a stator that is rotatable about an axis, the outer surface of the stator is a surface along the inner surface of the stator casing, and the inner surface of the stator is the outer surface of the support ring. It is characterized by being formed by an arcuate surface along.

  The gap between the outer surface of the stator and the inner surface of the stator casing can be made equal in any position on the outer surface of the stator. The relationship between the inner side surface of the stator and the outer side surface of the support ring is the same. Therefore, the gap that the inner and outer surfaces of the stator face can be minimized.

  The stator structure of the axial compressor according to the invention of claim 2 is characterized in that the inner surface of the stator casing, the outer surface of the stator, the inner surface of the stator, and the outer surface of the support ring are connected to the output shaft. It is characterized by being formed with a concentric cylindrical surface at the center.

  That is, the inner surface of the stator casing, the inner and outer surfaces of the stator, and the outer surface of the support ring are formed by concentric cylindrical surfaces. Since the stator casing, the stator, and the support ring do not rotate, these surfaces may have a shape that allows rotation about the support shaft of the stator. Therefore, it is formed by a concentric cylindrical surface centering on the output shaft.

  According to the stator structure of the axial compressor according to the present invention, the gap between the stator, the stator casing, and the support ring can be reduced as much as possible, and compressed air can flow out to the subsequent stage under unforeseen circumstances. The pressure can be increased to a desired size with an axial compressor.

  In addition, according to the stator structure of the axial compressor according to the second aspect of the present invention, since each of the surfaces is formed by concentric cylindrical surfaces, the processing of these surfaces is simplified and the processing accuracy is improved. Is easily secured.

It is a figure explaining the stator structure of the axial flow compressor concerning this invention, and is a schematic front view of the stator cut and shown by a plane in a direction perpendicular to the rotor shaft. It is a figure explaining the structure of an axial flow type compressor, and is a schematic sectional drawing cut | disconnected and shown by the surface containing a rotor axis | shaft. It is a figure explaining the conventional stator structure, and is a figure equivalent to FIG.

  Hereinafter, a stator structure of an axial compressor according to the present invention will be described in detail based on the illustrated preferred embodiment. In addition, the same code | symbol is attached | subjected about the part same as the structure shown in FIG. 2 and FIG.

  FIG. 1 is a front view of a stator having a structure according to the present invention, a view cut along a plane orthogonal to the output shaft 3, and corresponds to FIG. An appropriate number of stators 11 are juxtaposed in the stator casing 10 in the circumferential direction of a circle centered on the output shaft 3. Each of the stators 11 is supported at its outer end so as to be rotatable about the outer shaft 12a. The inner end of the stator 11 is supported by a support ring 13 so as to be rotatable about the inner shaft 12b. The outer shaft 11a and the inner shaft 11b are in the radial direction of the rotating shaft 3 and are on the same straight line. That is, the stator 11 rotates around the stator casing 10 and the support ring 13 with the radial direction of the output shaft 3 as an axis. It is supported movably.

  Both the inner surface 10b of the stator casing 10 and the outer surface 11a of the stator 11 are formed by concentric cylindrical surfaces with the output shaft 3 as the center. Similarly, the inner surface 11 b of the stator 11 and the outer surface 13 a of the support ring 13 are also formed by concentric cylindrical surfaces with the output shaft 3 as the center.

  In the stator structure configured as described above, when the stator 11 is rotated about the outer shaft 12a and the inner shaft 12b, the angle is changed between the adjacent stators 11, so that the opening between them is also Be changed. Compressed air flows from between the stators 11 and is supplied to the subsequent rotor 4a.

  As described above, the inner surface 10a of the stator casing 10 and the outer surface 11a of the stator 11 are formed of concentric cylindrical surfaces, or the stator 11 can be provided with a minimum gap therebetween. Further, since the inner side surface 11b of the stator 11 and the outer side surface 13a of the support ring 13 are also formed of concentric cylindrical surfaces, the stator 11 can be provided with a minimum gap therebetween. Therefore, the flow path of the compressed air can be almost eliminated other than flowing from between the adjacent stators 11, and it becomes easy to obtain the designed compressed air.

  In the embodiment shown in FIG. 1, the inner surface 10 a of the stator casing 10, the inner and outer surfaces 11 a and 11 b of the stator 11, and the outer surface 13 a of the support ring 13 are formed by concentric cylindrical surfaces around the output shaft 3. However, the surfaces facing each other may be similar to each other. Since the stator casing 10, the stator 11, and the support ring 13 do not need to rotate around the output shaft 3, they can have any shape. The inner surface 10a of the stator casing 10 needs to have a shape that allows the rotor 4a to rotate.

  According to the stator structure of the axial compressor according to the present invention, the unexpected flow path of the compressed air can be closed with the structure without the need for a seal member or the like, so that the output of the operation of the axial compressor can be stabilized. Contribute.

1 Axial flow compressor 3 Output shaft 4 Rotor shaft
4a Rotor 5 Air inlet
10 Stator casing
10a Inside surface
11 Stator
11a External side
11b Inside surface
12a Outer shaft
12b Inner shaft
13 Support ring
13a External side

Claims (2)

In an axial flow compressor including a stator that is supported by a stator casing and a support ring with a support shaft in a radial direction centered on the output shaft and is rotatable about the support shaft,
An axial flow compressor characterized in that the outer surface of the stator is formed by a surface along the inner surface of the stator casing, and the inner surface of the stator is formed by an arcuate surface along the outer surface of the support ring. Stator structure.   The inner surface of the stator casing, the outer surface of the stator, the inner surface of the stator, and the outer surface of the support ring are formed by concentric cylindrical surfaces centered on the output shaft. The stator structure of the axial-flow compressor described in 1.

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