COMPRESSOR SYSTEM AND BUNDLE MOVEMENT METHOD

Abstract

A compressor system includes: a driving machine including a drive shaft that rotates around an axis; a high-pressure compressor driven by transmission of rotation of the drive shaft and configured to compress a fluid; and a low-pressure compressor disposed on an opposite side of the driving machine with the high-pressure compressor interposed therebetween in an axial direction in which the axis extends and driven by transmission of rotation of the drive shaft. The high-pressure compressor includes a high-pressure bundle including a high-pressure rotor shaft that rotates around the axis together with the drive shaft and a plurality of high-pressure impellers, and a high-pressure casing. The low-pressure compressor includes a low-pressure bundle including a low-pressure rotor shaft that rotates around the axis together with the drive shaft and the high-pressure rotor shaft and a plurality of low-pressure impellers, and a low-pressure casing.

Description

TECHNICAL FIELD

The present disclosure relates to a compressor system and a bundle movement method.

This application claims priority from JP 2023-022727 filed in Japan on Feb. 16, 2023, and the contents of which are incorporated herein by reference.

BACKGROUND ART

A centrifugal compressor causes gases to pass through a rotating impeller, and compresses the gases using a centrifugal force generated when the gases flow. As the centrifugal compressor, a multistage centrifugal compressor is known in which a plurality of the impellers are included and the gas is compressed in stages. In a centrifugal compressor, a structure is known in which a bundle in which a diaphragm and a rotor are integrally formed is disposed in the inside of a casing.

Such a centrifugal compressor is driven by a driving machine (a steam turbine or an electric motor). In this case, there is a compressor system in which a high-pressure compressor and a low-pressure compressor are connected in series to one driving machine, and the two compressors are driven by the one driving machine.

For example, Patent Document 1 describes a compressor system in which a first compressor that is a low-pressure side compressor and a second compressor that is a high-pressure side compressor are disposed so as to sandwich one driving machine.

Citation List

Patent Literature

• • Patent Document 1: JP 6288886 B

SUMMARY OF INVENTION

Technical Problem

When a structure in which a bundle is disposed in the inside of the casing is adopted for the high-pressure compressor and the low-pressure compressor disposed in series as described above, it is required to secure a space adjacent to each compressor in the axial direction for disassembly and assembly for maintenance or the like. That is, it is required to separately secure a space for moving the bundle for each of the high-pressure compressor and the low-pressure compressor. However, individually securing a space only for moving the bundle in the vicinity of the high-pressure compressor, the low-pressure compressor, and the driving machine increases a restriction of an installation location. Thus, there is a problem that it is desired to reduce the space for moving the bundle with respect to a plurality of the compressors.

The present disclosure provides a compressor system and a bundle movement method that can reduce the space required for moving the bundle with respect to the plurality of compressors.

Solution to Problem

A compressor system according to the present disclosure includes a driving machine including a drive shaft that rotates around an axis, a high-pressure compressor that is driven by transmission of rotation of the drive shaft and compresses a fluid, and a low-pressure compressor disposed on an opposite side of the driving machine with the high-pressure compressor interposed therebetween in an axial direction in which the axis extends and driven by transmission of rotation of the drive shaft, in which the high-pressure compressor includes a high-pressure bundle including a high-pressure rotor shaft that rotates around the axis together with the drive shaft and a plurality of high-pressure impellers, and a high-pressure casing that accommodates the high-pressure bundle and is formed in a tubular shape centered on the axis, the low-pressure compressor includes a low-pressure bundle including a low-pressure rotor shaft that rotates around the axis together with the drive shaft and the high-pressure rotor shaft and a plurality of low-pressure impellers, and a low-pressure casing that accommodates the low-pressure bundle and is formed in a tubular shape centered on the axis, when viewed from the axial direction, a minimum inside diameter of the low-pressure casing is larger than a maximum outside diameter of the high-pressure bundle, and the high-pressure bundle is movable so that a position of the high-pressure bundle in the axial direction overlaps a position of the low-pressure casing in the axial direction in a state in which the low-pressure casing is fixed on a base plate.

A bundle movement method according to the present disclosure is the bundle movement method for a compressor system, the compressor system includes a drive shaft that rotates around an axis, a high-pressure compressor that is driven by transmission of rotation of the drive shaft and compresses a fluid, and a low-pressure compressor disposed on an opposite side of the driving machine with the high-pressure compressor interposed therebetween in an axial direction in which the axis extends and driven by transmission of rotation of the drive shaft, in which the high-pressure compressor includes a high-pressure bundle including a high-pressure rotor shaft that rotates around the axis together with the drive shaft and a plurality of high-pressure impellers, and a high-pressure casing that accommodates the high-pressure bundle and is formed in a tubular shape centered on the axis, and the low-pressure compressor includes a low-pressure bundle including a low-pressure rotor shaft that rotates around the axis together with the drive shaft and the high-pressure rotor shaft and a plurality of low-pressure impellers, and a low-pressure casing that accommodates the low-pressure bundle and is formed in a tubular shape centered on the axis, and when viewed from the axial direction, a minimum inside diameter of the low-pressure casing is larger than a maximum outside diameter of the high-pressure bundle, and the bundle movement method includes a step in which the high-pressure bundle is moved in the inside of the low-pressure casing so that a position of the high-pressure bundle in the axial direction overlaps a position of the low-pressure casing in the axial direction in a state in which the low-pressure casing is fixed on a base plate.

Advantageous Effects of Invention

According to a compressor system and a bundle movement method of the present disclosure, a space required for moving a bundle with respect to a plurality of compressors can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a compressor system according to an embodiment.

FIG. 2 is a flow diagram illustrating a maintenance method for the compressor system according to the present embodiment.

FIG. 3 is a schematic diagram illustrating a state in which a low-pressure bundle is moved from a low-pressure casing in the maintenance method for the compressor system according to the present embodiment.

FIG. 4 is a flow diagram illustrating steps of moving a high-pressure bundle of the compressor system according to the present embodiment.

FIG. 5 is a schematic diagram illustrating a state in which a height adjustment jig is disposed in the maintenance method for the compressor system according to the present embodiment.

FIG. 6 is a schematic diagram illustrating a state in which the high-pressure bundle moves on the low-pressure casing in the maintenance method for the compressor system according to the present embodiment.

FIG. 7 is a schematic diagram illustrating a state in which the high-pressure bundle is moved to an adjustment position in the maintenance method for the compressor system according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments for implementing a compressor system 1 and a bundle movement method according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited only to these embodiments.

Configuration of Compressor System

Hereinafter, the compressor system 1 according to the embodiment of the present disclosure will be described with reference to FIGS. 1 to 7. The compressor system 1 is disposed in, for example, a chemical plant such as an ammonia plant. As illustrated in FIG. 1, the compressor system 1 includes a steam turbine (driving machine) 2, an electric motor 4, a transmission 3, a high-pressure compressor 5, and a low-pressure compressor 6. The electric motor 4, the transmission 3, the steam turbine 2, the high-pressure compressor 5, and the low-pressure compressor 6 are coaxially disposed so that central axes of the respective rotors coincide with an axis O of the steam turbine 2.

Note that, hereinafter, a direction in which the axis O extends is referred to as an axial direction Da. The radial direction with respect to the axis O is simply referred to as a radial direction Dr. A part of the radial direction Dr is referred to as a vertical direction. In addition, in the compressor system 1, a side on which the steam turbine 2 is disposed with respect to the high-pressure compressor 5 is referred to as a first side Dal in the axial direction Da. In addition, in the compressor system 1, a side on which the low-pressure compressor 6 is disposed with respect to the high-pressure compressor 5 is referred to as a second side Da2 in the axial direction Da.

The steam turbine 2 is a driving machine that drives the high-pressure compressor 5 and the low-pressure compressor 6 by using steam generated in accordance with processing of a process gas (fluid). The steam turbine 2 in the present embodiment includes a turbine rotor (drive shaft) 21. The turbine rotor 21 is rotatable about the axis O.

The transmission 3 increases or decreases the speed of rotation of the electric motor 4 by a plurality of gears to transmit the rotation of the electric motor 4 to the steam turbine 2. The transmission 3 is disposed on the first side Da1 in the axial direction Da with respect to the steam turbine 2. The transmission 3 includes a transmission rotor 31. The transmission rotor 31 is connected to the turbine rotor 21 via a coupling. The transmission rotor 31 is rotatable about the axis O.

The electric motor 4 is a rotary machine that can assist rotation of the steam turbine 2. The electric motor 4 is applied with a voltage from the outside and is rotated at a rotational speed based on the magnitude of the applied voltage. The electric motor 4 is disposed on the first side Da1 in the axial direction Da with respect to the transmission 3. The electric motor 4 includes an electric motor rotor 41. The electric motor rotor 41 is connected to the transmission rotor 31 via a coupling. The rotor is rotatable about an axis O.

The high-pressure compressor 5 is driven by the rotation of the turbine rotor 21 being transmitted thereto, and compresses the process gas (fluid). The high-pressure compressor 5 further compresses the process gas after being compressed by the low-pressure compressor 6. The high-pressure compressor 5 is disposed on the second side Da2 in the axial direction Da with respect to the steam turbine 2. The high-pressure compressor 5 is disposed at a position so close to the steam turbine 2 in the axial direction Da that a high-pressure bundle 51 described later cannot be disposed. That is, a space in which the high-pressure bundle 51 can be disposed is not secured between the high-pressure compressor 5 and the steam turbine 2 in the axial direction Da. The high-pressure compressor 5 includes the high-pressure bundle 51 and a high-pressure casing 52.

The high-pressure bundle 51 is formed in a cylindrical shape centered on the axis O. The high-pressure bundle 51 extends in the axial direction Da. The high-pressure bundle 51 includes a high-pressure rotor shaft 511 and a plurality of high-pressure impellers 512. The high-pressure rotor shaft 511 is connected to the turbine rotor 21 via a coupling. The high-pressure rotor shaft 511 is connected to the turbine rotor 21 from the side opposite to the transmission rotor 31 in the axial direction Da. The high-pressure rotor shaft 511 is rotatable around the axis O together with the turbine rotor 21. The plurality of high-pressure impellers 512 are fixed to the high-pressure rotor shaft 511 at intervals in the axial direction Da. Each high-pressure impeller 512 compresses the process gas by rotating around the axis O together with the high-pressure rotor shaft 511.

The high-pressure bundle 51 is accommodated in the inside of the high-pressure casing 52. The high-pressure casing 52 is disposed so as to cover the high-pressure bundle 51 from an outer side Dro in the radial direction Dr. The high-pressure casing 52 is installed on a base plate (not illustrated). The high-pressure casing 52 of the present embodiment accommodates the high-pressure bundle 51 so as not to be movable in the vertical direction. Furthermore, the high-pressure casing 52 accommodates the high-pressure bundle 51 so as to be movable only to the second side Da2 in the axial direction Da. The high-pressure casing 52 includes a high-pressure casing main body 521, a high-pressure movement restricting portion (movement restricting portion) 522, a high-pressure inlet nozzle 523, a high-pressure extraction nozzle 524, and a high-pressure outlet nozzle 525.

The high-pressure casing main body 521 accommodates the high-pressure bundle 51 on an inner side Dri in the radial direction Dr. The high-pressure casing main body 521 accommodates the high-pressure bundle 51 in a state of being insertable into and removable from the second side Da2 in the axial direction Da. The high-pressure casing main body 521 is formed in a tubular shape centered on the axis O. The high-pressure casing main body 521 extends in the axial direction Da. The central axis of the high-pressure casing main body 521 is disposed at a position that coincides with the axis O when viewed from the axial direction Da. One end portion (second side Da2) of the high-pressure casing main body 521 in the axial direction Da is opened with a size in which the high-pressure bundle 51 can be inserted. In the present embodiment, the high-pressure casing main body 521 is opened at an end portion farthest from the steam turbine 2 in the axial direction Da. Thus, the high-pressure casing main body 521 is opened in a state in which the high-pressure bundle 51 is insertable and removable toward the low-pressure compressor 6 so as to be separated from the steam turbine 2 in the axial direction Da.

The high-pressure movement restricting portion 522 restricts the movement of the high-pressure bundle 51 approaching the steam turbine 2 in the axial direction Da. The high-pressure movement restricting portion 522 is formed at the other end portion (first side Da1) of the high-pressure casing main body 521 in the axial direction Da. The high-pressure movement restricting portion 522 of the present embodiment protrudes to the inner side Dri in the radial direction Dr with respect to the high-pressure casing main body 521. The high-pressure movement restricting portion 522 is formed as one member (for example, an end plate) integrated with the high-pressure casing main body 521. The high-pressure movement restricting portion 522 has a plate shape extending so as to be orthogonal to the axial direction Da. An opening having a size in which the high-pressure rotor shaft 511 can be inserted and the high-pressure bundle 51 cannot be inserted is formed in a central portion of the high-pressure movement restricting portion 522.

The high pressure inlet nozzle 523 introduces the process gas into the high pressure impeller 512 in the inside of the high pressure bundle 51. The high-pressure inlet nozzle 523 is formed so as to protrude to the outer side Dro in the radial direction Dr with respect to the high-pressure casing main body 521. The high-pressure inlet nozzle 523 of the present embodiment extends downward in the vertical direction with respect to the high-pressure casing main body 521. The high-pressure inlet nozzle 523 is formed as one member integrated with the high-pressure casing main body 521. A pipe connected to a supply source (not illustrated) of the process gas is connected to the high-pressure inlet nozzle 523.

The high-pressure extraction nozzle 524 extracts the process gas in the inside of the high-pressure bundle 51. The high-pressure extraction nozzle 524 is formed so as to protrude to the outer side Dro in the radial direction Dr with respect to the high-pressure casing main body 521. The high-pressure extraction nozzle 524 of the present embodiment extends upward in the vertical direction with respect to the high-pressure casing main body 521. The high-pressure extraction nozzle 524 is disposed to be separated from the high-pressure inlet nozzle 523 on the first side Da1 in the axial direction Da. The high-pressure extraction nozzle 524 is formed as one member integrated with the high-pressure casing main body 521. A pipe for supplying the extracted process gas is connected to the high-pressure extraction nozzle 524.

The high-pressure outlet nozzle 525 discharges the process gas in the inside of the high-pressure bundle 51 to the outside. The high-pressure outlet nozzle 525 is formed so as to protrude to the outer side Dro in the radial direction Dr with respect to the high-pressure casing main body 521. The high-pressure outlet nozzle 525 of the present embodiment extends downward in the vertical direction with respect to the high-pressure casing main body 521. The high-pressure outlet nozzle 525 is disposed to be separated from the high-pressure inlet nozzle 523 and the high-pressure extraction nozzle 524 on the first side Da1 in the axial direction Da. The high-pressure outlet nozzle 525 is formed as one member integrated with the high-pressure casing main body 521. A pipe connected to a supply destination (not illustrated) of the process gas is connected to the high-pressure outlet nozzle 525.

The low-pressure compressor 6 is driven by the rotation of the turbine rotor 21 being transmitted via the high-pressure compressor 5. The low-pressure compressor 6 compresses the process gas before the process gas is introduced into the high-pressure compressor 5. The low-pressure compressor 6 is disposed on the second side Da2 in the axial direction Da with respect to the high-pressure compressor 5. The low-pressure compressor 6 is disposed on an opposite side of the steam turbine 2 with the high-pressure compressor 5 interposed therebetween in the axial direction Da. The low-pressure compressor 6 is disposed at a position so close to the high-pressure compressor 5 in the axial direction Da that the high-pressure bundle 51 cannot be disposed. That is, a space in which the high-pressure bundle 51 can be disposed is not secured between the high-pressure compressor 5 and the low-pressure compressor 6 in the axial direction Da. The low-pressure compressor 6 includes a low-pressure bundle 61 and a low-pressure casing 62.

The low-pressure bundle 61 is formed in a cylindrical shape centered on the axis O. The low-pressure bundle 61 extends in the axial direction Da. When viewed from the axial direction Da, the maximum outside diameter of the low-pressure bundle 61 is larger than the maximum outside diameter of the high-pressure bundle 51. The low-pressure bundle 61 includes a low-pressure rotor shaft 611 and a plurality of low-pressure impellers 612. The low-pressure rotor shaft 611 is connected to the high-pressure rotor shaft 511 via a coupling. The low-pressure rotor shaft 611 is connected to the high-pressure rotor shaft 511 from an opposite side of the turbine rotor 21 in the axial direction Da. The low-pressure rotor shaft 611 is rotatable around the axis O together with the high-pressure rotor shaft 511. The plurality of low-pressure impellers 612 are fixed to the rotor shaft at intervals in the axial direction Da. Each low-pressure impeller 612 compresses the process gas by rotating around the axis O together with the low-pressure rotor shaft 611. The maximum outside diameters of the plurality of low-pressure impellers 612 are larger than the maximum outside diameters of the plurality of high-pressure impellers 512.

The low-pressure bundle 61 is accommodated in the inside of the low-pressure casing 62. The low-pressure casing 62 is disposed so as to cover the low-pressure bundle 61 from the outer side Dro in the radial direction Dr. When viewed from the axial direction Da, the minimum inside diameter of the low-pressure casing 62 is larger than the maximum outside diameter of the high-pressure bundle 51. The low-pressure casing 62 is installed on a base plate. The low-pressure casing 62 includes a low-pressure casing main body 621, a low-pressure movement restricting portion 622, a low-pressure inlet nozzle 623, and a low-pressure outlet nozzle 624.

The low-pressure casing main body 621 accommodates the low-pressure bundle 61 on the inner side Dri in the radial direction Dr. The low-pressure casing main body 621 accommodates the low-pressure bundle 61 in a state of being insertable into and removable from the second side Da2 in the axial direction Da. The low-pressure casing main body 621 is formed in a tubular shape centered on the axis O. The low-pressure casing main body 621 extends in the axial direction Da. The central axis of the low-pressure casing main body 621 is disposed at a position that coincides with the axis O when viewed from the axial direction Da. Thus, the low-pressure casing main body 621 is disposed so that the position of the central axis of the low-pressure casing main body 621 coincides with the position of the central axis of the high-pressure casing main body 521. One end portion (second side Da2) of the low-pressure casing main body 621 in the axial direction Da is opened with a size in which the low-pressure bundle 61 can be inserted. In the present embodiment, the low-pressure casing main body 621 is opened at an end portion farthest from the steam turbine 2 in the axial direction Da. Thus, the low-pressure casing main body 621 is opened in a state in which the low-pressure bundle 61 is insertable and removable so as to be separated from the steam turbine 2 and the high pressure compressor 5 in the axial direction Da.

The low-pressure movement restricting portion 622 is formed at the other end portion (first side Da1) of the low-pressure casing 62 in the axial direction Da. The low-pressure movement restricting portion 622 restricts the movement of the low-pressure bundle 61 approaching the steam turbine 2 in the axial direction Da. The low-pressure movement restricting portion 622 of the present embodiment protrudes to the inner side Dri in the radial direction Dr with respect to the low-pressure casing main body 621. The low-pressure movement restricting portion 622 is formed as one member (for example, an end plate) integrated with the low-pressure casing main body 621. The low-pressure movement restricting portion 622 has a plate shape extending so as to be orthogonal to the axial direction Da. An opening having a size in which the low-pressure rotor shaft 611 and the high-pressure bundle 51 can be inserted and the low-pressure bundle 61 cannot be inserted is formed in a central portion of the low-pressure movement restricting portion 622. A position at which the opening of the central portion of the low-pressure movement restricting portion 622 is formed is a position of the minimum inside diameter in the low-pressure casing 62. Thus, the high-pressure bundle 51 has a size in which the high-pressure bundle 51 is movable in the axial direction Da to the inside of the low-pressure casing main body 621 through the opening in the central portion of the low-pressure movement restricting portion 622.

The low pressure inlet nozzle 623 introduces the process gas into the low pressure impeller 612 in the inside of the low pressure bundle 61. The low pressure inlet nozzle 623 is formed so as to protrude to the outer side Dro in the radial direction Dr with respect to the low-pressure casing main body 621. The low-pressure inlet nozzle 623 of the present embodiment extends downward in the vertical direction with respect to the low-pressure casing main body 621. The low-pressure inlet nozzle 623 is formed as one member integrated with the low-pressure casing main body 621. A pipe connected to a supply source (not illustrated) of the process gas is connected to the low-pressure inlet nozzle 623.

The low-pressure outlet nozzle 624 discharges the process gas in the inside of the low pressure bundle 61 to the outside. The low-pressure outlet nozzle 624 is formed so as to protrude to the outer side Dro in the radial direction Dr with respect to the low-pressure casing main body 621. The low-pressure outlet nozzle 624 of the present embodiment extends downward in the vertical direction with respect to the low-pressure casing main body 621. The low-pressure outlet nozzle 624 is disposed to be separated from the low-pressure inlet nozzle 623 on the first side Da1 in the axial direction Da. The low-pressure outlet nozzle 624 is formed as one member integrated with the low-pressure casing main body 621. A pipe connected to a supply destination (for example, the high-pressure inlet nozzle 523) of the process gas is connected to the low-pressure outlet nozzle 624.

Procedure of Maintenance Method (bundle Movement Method) of Compressor System

Next, a maintenance method (bundle movement method) S1 of the compressor system 1 described above will be described. As illustrated in FIG. 2, the maintenance method S1 of the compressor system 1 mainly includes a step S10 in which the low-pressure bundle 61 is moved, a step S20 in which the high-pressure bundle 51 is moved, and a step S30 in which maintenance is performed on the low-pressure bundle 61 and the high-pressure bundle 51.

As illustrated in FIG. 3, in the step S10 in which the low-pressure bundle 61 is moved, the low-pressure bundle 61 is removed from the low-pressure casing 62. In the step S10 in which the low-pressure bundle 61 is moved, first, the connection between the low-pressure rotor shaft 611 and the high-pressure rotor shaft 511 is released. Thereafter, the low-pressure bundle 61 is moved in a state in which the low-pressure casing 62 is fixed on the base plate. At this time, the pipes remain in a state of being fixed to the low-pressure inlet nozzle 623 and the low-pressure outlet nozzle 624. That is, the low-pressure casing 62 is not moved at all from the position during an operation. The low-pressure bundle 61 is moved to the second side Da2 in the axial direction Da with respect to the low-pressure casing 62 by a wire being pulled by using a lifting machine such as a crane. The low-pressure bundle 61 is moved to a position at which the low-pressure casing 62 and the low-pressure bundle 61 do not overlap each other in the axial direction Da. Thereafter, the low-pressure bundle 61 is lifted up via the wire by using the lifting machine such as the crane, and is moved to an adjustment position at which maintenance is performed.

In the step S20 in which the high-pressure bundle 51 is moved, the high-pressure bundle 51 is removed from the high-pressure casing 52 and the low-pressure casing 62. In the step S20 in which the high-pressure bundle 51 is moved, the high-pressure bundle 51 is moved in the low-pressure casing 62. To be specific, as illustrated in FIG. 4, the step S20 in which the high-pressure bundle 51 of the present embodiment is moved mainly includes a step S21 in which a height adjustment jig 9 is disposed, a step S22 in which the high-pressure bundle 51 is moved in the axial direction Da through the inside of the low-pressure casing 62, and a step S23 in which the high-pressure bundle 51 is moved to the adjustment position.

As illustrated in FIG. 5, in the step S21 in which the height adjustment jig 9 is disposed, the height adjustment jig 9 is disposed with respect to the low-pressure casing 62. The height adjustment jig 9 forms an adjustment surface 90 with respect to the low-pressure casing 62. The adjustment surface 90 is a smooth surface in which a position of the adjustment surface 90 in the vertical direction coincides with a position of the outside surface of the high-pressure bundle 51 disposed in the high-pressure casing 52 in the vertical direction. The height adjustment jig 9 is configured such that the high-pressure bundle 51 can be placed on the adjustment surface 90. In the present embodiment, the height adjustment jig 9 includes an external height adjustment jig 9A and an internal height adjustment jig 9B.

The external height adjustment jig 9A forms an external adjustment surface 90A, which is an adjustment surface 90, between the low-pressure casing 62 and the high-pressure casing 52. The external height adjustment jig 9A is disposed between the low-pressure casing 62 and the high-pressure casing 52 in the axial direction Da. The external height adjustment jig 9A is fixed to the base plate, the low-pressure casing 62, or the high-pressure casing 52. The external height adjustment jig 9A is disposed so as to fill a gap between the low-pressure casing 62 and the high-pressure casing 52 in the axial direction Da when viewed from a direction orthogonal to the axial direction Da.

The internal height adjustment jig 9B forms an internal adjustment surface 90B, which is the adjustment surface 90, in the inside of the low-pressure casing 62. The internal height adjustment jig 9B is disposed at a position overlapping the low-pressure casing main body 621 in the axial direction Da. The internal height adjustment jig 9B is attached to the inside of the low-pressure casing main body 621. The internal height adjustment jig 9B is disposed so as to cover a region of half or more of the inside surface of the low-pressure casing main body 621 when viewed from the direction orthogonal to the axial direction Da.

In the step S21 in which the height adjustment jig 9 is disposed, each of the external height adjustment jig 9A and the internal height adjustment jig 9B is disposed in a state of not being movable.

In the step S22 in which the high-pressure bundle 51 is moved in the axial direction Da through the inside of the low-pressure casing 62, as illustrated in FIG. 6, first, the connection between the turbine rotor 21 and the high-pressure rotor shaft 511 is released. Thereafter, the high-pressure bundle 51 is moved in a state in which the high-pressure casing 52 and the low-pressure casing 62 are fixed on the base plate. At this time, the pipes remain in a state of being fixed to the high-pressure inlet nozzle 523, the high-pressure extraction nozzle 524, the high-pressure outlet nozzle 525, the low-pressure inlet nozzle 623, and the low-pressure outlet nozzle 624. That is, the high-pressure casing 52 and the low-pressure casing 62 are not moved at all from the positions during an operation. Thus, in the step S22 in which the high-pressure bundle 51 is moved in the axial direction Da through the inside of the low-pressure casing 62, the central axis of the high-pressure casing 52 and the central axis of the low-pressure casing 62 are always disposed at positions that coincide with the axial line O when viewed from the axial direction Da. The high-pressure bundle 51 is moved to the second side Da2 in the axial direction Da with respect to the high-pressure casing 52 by the wire being pulled by using the lifting machine such as the crane. The high-pressure bundle 51 is moved to a position at which the high-pressure casing 52 and the low-pressure casing 62 do not overlap the high-pressure bundle 51 in the axial direction Da. At this time, the high-pressure bundle 51 is moved only in the axial direction Da with respect to the high-pressure casing 52 from the inside of the high-pressure casing 52 to the inside of the low-pressure casing 62.

To be specific, the high-pressure bundle 51 is moved straight from the inside of the high-pressure casing 52 to the second side Da in the axial direction Da2 on the external height adjustment jig 9A. Thereafter, the high-pressure bundle 51 is moved straight from on the external height adjustment jig 9A to on the internal height adjustment jig 9B to the second side Da2 in the axial direction Da through the opening of the central portion of the low-pressure movement restricting portion 622. Accordingly, the high-pressure bundle 51 is moved to the inside of the low-pressure casing 62 via the internal height adjustment jig 9B so that the position of the high-pressure bundle 51 in the axial direction Da overlaps the position of the low-pressure casing 62 in the axial direction Da. Thereafter, the high-pressure bundle 51 is moved straight to the second side Da2 in the axial direction Da to a position at which the low-pressure casing 62 and the high-pressure bundle 51 do not overlap each other in the axial direction Da. That is, the high-pressure bundle 51 is moved in a state in which the central axis of the high-pressure bundle 51 overlaps the axis O until the high-pressure bundle 51 is taken out from the inside of the high-pressure casing 52 to the outside of the low-pressure casing 62 through the inside of the low-pressure casing 62.

As illustrated in FIG. 7, in the step S23 in which the high-pressure bundle 51 is moved to the adjustment position, the high-pressure bundle 51 taken out to the outside of the low-pressure casing 62 is moved to the adjustment position at which maintenance is performed. The high-pressure bundle 51 is pulled up via the wire by using the lifting machine such as the crane at the outside of the low-pressure casing 62 (a position at which the high-pressure bundle 51 does not overlap the high-pressure casing 52 and the low-pressure casing 62 in the axial direction Da) and moved to the adjustment position.

In the step S30 in which the maintenance is performed on the low-pressure bundle 61 and the high-pressure bundle 5, the maintenance of the low-pressure bundle 61 and the high-pressure bundle 51 is performed at the adjustment position. At the same time, maintenance of the high-pressure casing 52 and the low-pressure casing 62 is also performed.

Actions and Effects

According to the compressor system 1 having the above-described configuration, when viewed from the axial direction Da, the minimum inside diameter of the low-pressure casing 62 is formed to be larger than the maximum outside diameter of the high-pressure bundle 51. Thus, the high-pressure bundle 51 is movable to the inside of the low-pressure casing main body 621 through the opening in the central portion of the low-pressure movement restricting portion 622 which is the position of the minimum inside diameter of the low-pressure casing 62. Thus, the high-pressure bundle 51 is moved so that the position of the high-pressure bundle 51 in the axial direction Da overlaps the position of the low-pressure casing 62 in the axial direction Da in a state in which the low-pressure casing 62 is fixed on the base plate. Thereafter, the high-pressure bundle 51 is moved from the inside of the low-pressure casing main body 621 to the outside of the low-pressure casing 62. In this way, the high-pressure bundle 51 is movable to the outside through the inside of the low-pressure casing 62. Thus, it is not required to secure a space for moving the high-pressure bundle 51 around the high-pressure compressor 5 such as between the high-pressure compressor 5 and the low-pressure compressor 6 or between the high-pressure compressor 5 and the steam turbine 2. Accordingly, a space required for moving a bundle with respect to a plurality of compressors can be reduced.

Further, when the high-pressure bundle 51 passes, the low-pressure casing 62 is fixed on the base plate. That is, it is not required to move the low-pressure casing 62. Thus, the disassembly work of the low-pressure casing 62 is not required. Thus, it is also not required to remove the pipes connected to the low-pressure inlet nozzle 623 and the low-pressure outlet nozzle 624. Thus, the work processes before and after the maintenance work can be simplified, and the work time can be shortened.

In addition, the high-pressure bundle 51 is moved only to the second side Da2 in the axial direction Da with respect to the high-pressure casing 52 to the inside of the low-pressure casing 62. Thus, it is not required to disassemble the high-pressure casing 52 in order to move the high-pressure bundle 51. As a result, the high-pressure casing 52 can also remain in a state of being fixed on the base plate. That is, it is not required to move the high-pressure casing 52. Thus, the disassembly work of the high-pressure casing 52 is not required. Thus, it is also not required to remove the pipes connected to the high-pressure inlet nozzle 523, the high-pressure extraction nozzle 524, and the high-pressure outlet nozzle 525. Thus, the work processes before and after the maintenance work can be simplified not only in the low-pressure casing 62 but also in the high-pressure casing 52, and the work time can be further shortened.

Further, the high-pressure casing 52 includes the high-pressure movement restricting portion 522 that restricts the movement of the high-pressure bundle 51 approaching the steam turbine 2 in the axial direction Da. Thus, the high-pressure bundle 51 cannot move to the first side Da1 in the axial direction Da with respect to the high-pressure casing main body 521 so as to approach the steam turbine 2. That is, the high-pressure bundle 51 is moved only to the second side Da2 in the axial direction Da with respect to the high-pressure casing main body 521. Thus, when the high-pressure bundle 51 is moved, the high-pressure bundle 51 is reliably moved to the inside of the low-pressure casing 62. Thus, it is not required to secure the space for moving the high-pressure bundle 51 between the high-pressure compressor 5 and the steam turbine 2. Accordingly, the degree of an installation position of the steam turbine 2 can be improved.

In addition, the high-pressure bundle 51 is moved in a state in which the external height adjustment jig 9A and the internal height adjustment jig 9B are disposed. Thus, the high-pressure bundle 51 moves through on the external adjustment surface 90A and then is moved onto the internal adjustment surface 90B in the inside of the low-pressure casing main body 621. At this time, the external adjustment surface 90A and the internal adjustment surface 90B are formed so that positions of the external adjustment surface 90A and the internal adjustment surface 90B in the vertical direction coincide with a position of the outside surface of the high-pressure bundle 51 in the vertical direction in a state of being disposed in the high-pressure casing 52. Thus, when the high-pressure bundle 51 is moved on the external adjustment surface 90A and the internal adjustment surface 90B, the position of the high-pressure bundle 51 in the vertical direction does not change from the state in which the high-pressure bundle 51 is accommodated in the inside of the high-pressure casing 52. That is, the high-pressure bundle 51 can move from the inside of the high-pressure casing main body 521 to the inside of the low-pressure casing main body 621 with high accuracy without being deviated in the vertical direction. Thus, the high-pressure casing 52 or the low-pressure casing 62 can be prevented from coming into contact with the high-pressure bundle 51 and being damaged while the high-pressure bundle 51 is being moved.

The high-pressure bundle 51 is moved in a state in which the central axis of the high-pressure casing 52 and the central axis of the low-pressure casing 62 are disposed at positions that coincide with the axial line O when viewed from the axial direction Da. That is, the high-pressure casing 52 and the low-pressure casing 62 are maintained in a state of being fixed on the base plate without the central axes of the high-pressure casing 52 and the low-pressure casing 62 being deviated. Thus, at the time of assembly after the movement of the high-pressure bundle 51, such as after the end of maintenance, the work of alignment adjustment for aligning the positions of the central axes of the high-pressure casing 52 and the low-pressure casing 62 with the axis O is substantially not required. Accordingly, the work processes before and after the movement of the high-pressure bundle 51 can be further simplified and the work time can be further shortened.

In addition, the high-pressure bundle 51 is moved with high accuracy from the inside of the high-pressure casing main body 521 to the inside of the low-pressure casing main body 621 by the external height adjustment jig 9A and the internal height adjustment jig 9B. Thus, the high-pressure bundle 51 can be prevented from largely coming into contact with the high-pressure casing 52 and the low-pressure casing 62 to deviate the positions of the high-pressure casing 52 and the low-pressure casing 62. Accordingly, the addition of the work of alignment adjustment for aligning the positions of the central axes of the high-pressure casing 52 and the low-pressure casing 62 with the axis O can be also suppressed. Thus, the work processes before and after the maintenance work can be further simplified, and the work time can be further shortened.

Other Embodiments

Although the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, specific configurations are not limited to these embodiments, and design changes and the like without departing from the gist of the present disclosure are also included.

For example, as long as the compressor system 1 includes the driving machine, the high-pressure compressor 5, and the low-pressure compressor 6, other devices need not be disposed. Thus, the compressor system 1 need not include the transmission 3 and the electric motor 4. In addition, in the compressor system 1, the electric motor 4 may be disposed as the driving machine instead of the steam turbine 2. Thus, the compressor system 1 may have a structure including only the electric motor 4, the high-pressure compressor 5, and the low-pressure compressor 6.

In addition, although the high-pressure casing 52 includes the high-pressure movement restricting portion 522, the high-pressure casing 52 is not limited to such a structure. For example, the high-pressure casing 52 need not include the high-pressure movement restricting portion 522. Even when the high-pressure movement restricting portion 522 is included, the high-pressure movement restricting portion 522 is not limited to be formed as a member integrated with the high-pressure casing main body 521. The high-pressure movement restricting portion 522 may be formed as a separate member (for example, a shearing ring) separable from the high-pressure casing main body 521.

Similarly, although the low-pressure casing 62 includes the low-pressure movement restricting portion 622, the low-pressure casing 62 is not limited to such a structure. For example, the low-pressure casing 62 need not include the low-pressure movement restricting portion 622. Even when the low-pressure movement restricting portion 622 is included, the low-pressure movement restricting portion 622 is not limited to be formed as a member integrated with the low-pressure casing main body 621. The low-pressure movement restricting portion 622 may be formed as a separate member (for example, a shearing ring) separable from the low-pressure casing main body 621.

In the present embodiment, the height adjustment jig 9 is disposed when the high-pressure bundle 51 is moved, but the present embodiment is not limited to disposing the height adjustment jig 9. For example, the inside of the low-pressure casing 62 may be moved without disposing the height adjustment jig 9 when the high-pressure bundle 51 is moved. Further, even when the height adjustment jig 9 is disposed when the high-pressure bundle 51 is moved, only one of the external height adjustment jig 9A and the internal height adjustment jig 9B may be disposed.

In the present embodiment, the bundle movement method is applied as the maintenance method S1 of the compressor system 1, but the bundle movement method is not limited to be applied only to the maintenance method. For example, the bundle movement method may be applied to disassembly or assembly of the compressor system 1. Further, when the high-pressure bundle 51 is inserted into the high-pressure casing 52 as in the assembly of the compressor system 1, the procedure of the above-described embodiment may be performed in the reverse order.

Supplementary Notes

The compressor system 1 and the bundle movement method described in the embodiments can be understood as follows, for example.

(1) A compressor system 1 according to a first aspect includes a driving machine including a drive shaft that rotates around an axis O, a high-pressure compressor 5 that is driven by transmission of rotation of the drive shaft and compresses a fluid, and a low-pressure compressor 6 disposed on an opposite side of the driving machine with the high-pressure compressor 5 interposed therebetween in an axial direction Da in which the axis O extends and driven by transmission of rotation of the drive shaft, in which the high-pressure compressor 5 includes a high-pressure bundle 51 including a high-pressure rotor shaft 511 that rotates around the axis O together with the drive shaft and a plurality of high-pressure impellers 512, and a high-pressure casing 52 that accommodates the high-pressure bundle 51 and is formed in a tubular shape centered on the axis O, the low-pressure compressor 6 includes a low-pressure bundle 61 including a low-pressure rotor shaft 611 that rotates around the axis O together with the drive shaft and the high-pressure rotor shaft 511 and a plurality of low-pressure impellers 612, and a low-pressure casing 62 that accommodates the low-pressure bundle 61 and is formed in a tubular shape centered on the axis O, when viewed from the axial direction Da, a minimum inside diameter of the low-pressure casing 62 is larger than a maximum outside diameter of the high-pressure bundle 51, and the high-pressure bundle 51 is movable so that a position of the high-pressure bundle 51 in the axial direction Da overlaps a position of the low-pressure casing 62 in the axial direction Da in a state in which the low-pressure casing 62 is fixed on a base plate.

Accordingly, the high-pressure bundle 51 is movable to the inside of the low-pressure casing 62. Thus, the high-pressure bundle 51 is moved so that the position of the high-pressure bundle 51 in the axial direction Da overlaps the position of the low-pressure casing 62 in the axial direction Da in a state in which the low-pressure casing 62 is fixed on the base plate. Thereafter, the high-pressure bundle 51 is moved from the inside of the low-pressure casing 62 to the outside of the low-pressure casing 62. In this way, the high-pressure bundle 51 is movable to the outside through the inside of the low-pressure casing 62. Thus, it is not required to secure a space for moving the high-pressure bundle 51 around the high-pressure compressor 5 such as between the high-pressure compressor 5 and the low-pressure compressor 6 or between the high-pressure compressor 5 and the steam turbine 2. Accordingly, the space required for moving the bundle with respect to the plurality of compressors can be reduced.

(2) The compressor system 1 according to a second aspect is the compressor system 1 according to (1), in which the high-pressure casing 52 includes a movement restricting portion that restricts movement of the high-pressure bundle 51 approaching the driving machine in the axial direction Da.

Accordingly, the high-pressure bundle 51 cannot move in the axial direction Da with respect to the high-pressure casing 52 so as to approach the steam turbine 2 due to the movement restricting portion. That is, the high-pressure bundle 51 is moved only to the one side in the axial direction Da with respect to the high-pressure casing 52. Thus, when the high-pressure bundle 51 is moved, the high-pressure bundle 51 is reliably moved to the inside of the low-pressure casing 62. Thus, it is not required to secure the space for moving the high-pressure bundle 51 between the high-pressure compressor 5 and the steam turbine 2. Accordingly, the degree of an installation position of the steam turbine 2 can be improved.

(3) A bundle movement method according to a third aspect is a bundle movement method for a compressor system 1, the compressor system 1 includes a drive shaft that rotates around an axis O, a high-pressure compressor 5 that is driven by transmission of rotation of the drive shaft and compresses a fluid, and a low-pressure compressor 6 disposed on an opposite side of the driving machine with the high-pressure compressor 5 interposed therebetween in an axial direction Da in which the axis O extends and driven by transmission of rotation of the drive shaft, in which the high-pressure compressor 5 includes a high-pressure bundle 51 including a high-pressure rotor shaft 511 that rotates around the axis O together with the drive shaft and a plurality of high-pressure impellers 512, and a high-pressure casing 52 that accommodates the high-pressure bundle 51 and is formed in a tubular shape centered on the axis O, and the low-pressure compressor 6 includes a low-pressure bundle 61 including a low-pressure rotor shaft 611 that rotates around the axis O together with the drive shaft and the high-pressure rotor shaft 511 and a plurality of low-pressure impellers 612, and a low-pressure casing 62 that accommodates the low-pressure bundle 61 and is formed in a tubular shape centered on the axis O, and when viewed from the axial direction Da, a minimum inside diameter of the low-pressure casing 62 is larger than a maximum outside diameter of the high-pressure bundle 51, and the bundle movement method includes a step 20 in which the high-pressure bundle 51 is moved in the inside of the low-pressure casing 62 so that a position of the high-pressure bundle 51 in the axial direction Da overlaps a position of the low-pressure casing 62 in the axial direction Da in a state in which the low-pressure casing 62 is fixed on a base plate.

Accordingly, the high-pressure bundle 51 is moved to the inside of the low-pressure casing 62. Thereafter, the high-pressure bundle 51 is moved from the inside of the low-pressure casing 62 to the outside of the low-pressure casing 62. In this way, the high-pressure bundle 51 is movable to the outside through the inside of the low-pressure casing 62. Thus, it is not required to secure a space for moving the high-pressure bundle 51 around the high-pressure compressor 5 such as between the high-pressure compressor 5 and the low-pressure compressor 6 or between the high-pressure compressor 5 and the steam turbine 2. Accordingly, the space required for moving the bundle with respect to the plurality of compressors can be reduced.

(4) The bundle movement method according to a fourth aspect is the bundle movement method according to (3), in which in the step S20 in which the high-pressure bundle 51 is moved, the high-pressure bundle 51 is moved only in the axial direction Da with respect to the high-pressure casing 52 to the inside of the low-pressure casing 62.

Accordingly, it is not required to disassemble the high-pressure casing 52 in order to move the high-pressure bundle 51. As a result, the high-pressure casing 52 can also remain in a state of being fixed on the base plate. That is, it is not required to move the high-pressure casing 52. Thus, the disassembly work of the high-pressure casing 52 is not required. Thus, it is also not required to remove the pipe connected to the high-pressure casing 52. Thus, the work processes before and after the maintenance work can be simplified not only in the low-pressure casing 62 but also in the high-pressure casing 52, and the work time can be further shortened.

(5) The bundle movement method according to a fifth aspect is the bundle movement method according to (3) or (4), and further includes a step S21 in which a height adjustment jig 9 is disposed, the height adjustment jig 9 forming an adjustment surface 90 with respect to the low-pressure casing 62, a position of the adjustment surface 90 in the vertical direction coinciding with a position of an outside surface of the high-pressure bundle 51 disposed in the high-pressure casing 52 in the vertical direction, in which in the step S20 in which the high-pressure bundle 51 is moved, the high-pressure bundle 51 is moved on the height adjustment jig 9.

Accordingly, the high-pressure bundle 51 moves through on the adjustment surface 90, and then is moved to the inside of the low-pressure casing 62. At this time, the adjustment surface 90 is formed so that a position of the adjustment surface 90 in the vertical direction coincides with a position of the outside surface of the high-pressure bundle 51 in the vertical direction in a state of being disposed in the high-pressure casing 52. Thus, when the high-pressure bundle 51 is moved on the adjustment surface 90, the position of the high-pressure bundle 51 in the vertical direction does not change from the state in which the high-pressure bundle 51 is accommodated in the inside of the high-pressure casing 52. That is, the high-pressure bundle 51 can move from the inside of the high-pressure casing 52 to the inside of the low-pressure casing 62 with high accuracy without being deviated in the vertical direction. Thus, the high-pressure casing 52 or the low-pressure casing 62 can be prevented from coming into contact with the high-pressure bundle 51 and being damaged while the high-pressure bundle 51 is being moved.

(6) The bundle movement method according to a sixth aspect is the bundle movement method according to any one of (3) to (5), in which in the step S20 in which the high-pressure bundle 51 is moved, the high-pressure bundle 51 is moved in a state in which a central shaft of the high-pressure casing 52 and a central shaft of the low-pressure casing 62 are disposed at positions that coincide with the axial line O when viewed from the axial direction Da.

Accordingly, the high-pressure casing 52 and the low-pressure casing 62 are maintained in a state of being fixed on the base plate without the central axes of the high-pressure casing 52 and the low-pressure casing 62 being deviated. Thus, at the time of assembly after the movement of the high-pressure bundle 51, the work of alignment adjustment for aligning the positions of the central axes of the high-pressure casing 52 and the low-pressure casing 62 with the axis O is substantially not required. Accordingly, the work processes before and after the movement of the high-pressure bundle 51 can be further simplified and the work time can be further shortened.

Industrial Applicability

According to a compressor system and a bundle movement method of the present disclosure, a space required for moving a bundle with respect to a plurality of compressors can be reduced.

REFERENCE SIGNS LIST

• • 1 Compressor system
  • O Axis
  • 2 Steam turbine
  • 21 Turbine rotor
  • 3 Transmission
  • 31 Transmission rotor
  • 4 Electric motor
  • 41 Electric motor rotor
  • 5 High-pressure compressor
  • 51 High-pressure bundle
  • 511 High-pressure rotor shaft
  • 512 High-pressure impeller
  • 52 High-pressure casing
  • 521 High-pressure casing main body
  • 522 High-pressure movement restricting portion
  • 523 High-pressure Inlet nozzle
  • 524 High-pressure extraction nozzle
  • 525 High-pressure outlet nozzle
  • 6 Low-pressure compressor
  • 61 Low-pressure bundle
  • 611 Low-pressure rotor shaft
  • 612 Low-pressure impeller
  • 62 Low-pressure casing
  • 621 Low-pressure casing main body
  • 622 Low-pressure movement restricting portion
  • 623 Low-pressure inlet nozzle
  • 624 Low-pressure outlet nozzle
  • Da Axial direction
  • Da1 First side
  • Da2 Second side
  • Dr Radial direction
  • Dro Outer side
  • Dri Inner side
  • S1 Compressor system maintenance method
  • S10 Step in which low-pressure bundle is moved
  • S20 Step in which high-pressure bundle is moved
  • S21 Step in which height adjusting jig is disposed
  • S22 Step in which high-pressure bundle is moved in axial direction through inside of low-pressure casing
  • S23 Step in which high-pressure bundle is moved to adjustment position
  • S30 Step in which maintenance is performed on low-pressure bundle and high-pressure bundle
  • 9 Height adjustment jig
  • 9A External height adjustment jig
  • 9B Internal height adjustment jig
  • 90 Adjustment surface
  • 90A External adjustment surface
  • 90B Internal adjustment surface

Claims

1. A compressor system comprising:

a driving machine including a drive shaft that rotates around an axis;

a high-pressure compressor driven by transmission of rotation of the drive shaft and configured to compress a fluid; and

a low-pressure compressor disposed on an opposite side of the driving machine with the high-pressure compressor interposed therebetween in an axial direction in which the axis extends and driven by transmission of rotation of the drive shaft, wherein

the high-pressure compressor includes

a high-pressure bundle including a high-pressure rotor shaft that rotates around the axis together with the drive shaft and a plurality of high-pressure impellers, and

a high-pressure casing configured to accommodate the high-pressure bundle and formed in a tubular shape centered on the axis,

the low-pressure compressor includes

a low-pressure bundle including a low-pressure rotor shaft that rotates around the axis together with the drive shaft and the high-pressure rotor shaft and a plurality of low-pressure impellers, and

a low-pressure casing configured to accommodate the low-pressure bundle and formed in a tubular shape centered on the axis,

when viewed from the axial direction, a minimum inside diameter of the low-pressure casing is larger than a maximum outside diameter of the high-pressure bundle, and

the high-pressure bundle is movable, and a position of the high-pressure bundle in the axial direction overlaps a position of the low-pressure casing in the axial direction in a state in which the low-pressure casing is fixed on a base plate.

2. The compressor system according to claim 1, wherein

the high-pressure casing includes a movement restricting portion configured to restrict movement of the high-pressure bundle approaching the driving machine in the axial direction.

3. A bundle movement method for a compressor system, the compressor system comprising:

a drive shaft that rotates around an axis;

a high-pressure compressor that is driven by transmission of rotation of the drive shaft and configured to compress a fluid; and

a low-pressure compressor disposed on an opposite side of the driving machine with the high-pressure compressor interposed therebetween in an axial direction in which the axis extends and driven by transmission of rotation of the drive shaft, wherein

the high-pressure compressor includes

a high-pressure bundle including a high-pressure rotor shaft that rotates around the axis together with the drive shaft and a plurality of high-pressure impellers, and

a high-pressure casing configured to accommodate the high-pressure bundle and is formed in a tubular shape centered on the axis, and

the low-pressure compressor includes

a low-pressure bundle including a low-pressure rotor shaft that rotates around the axis together with the drive shaft and the high-pressure rotor shaft and a plurality of low-pressure impellers, and

a low-pressure casing configured to accommodate the low-pressure bundle and is formed in a tubular shape centered on the axis, and

when viewed from the axial direction, a minimum inside diameter of the low-pressure casing is larger than a maximum outside diameter of the high-pressure bundle, the bundle movement method comprising: moving the high-pressure bundle in the inside of the low-pressure casing and a position of the high-pressure bundle in the axial direction overlaps a position of the low-pressure casing in the axial direction in a state in which the low-pressure casing is fixed on a base plate.

4. The bundle movement method according to claim 3, wherein

in the moving the high-pressure bundle, the high-pressure bundle is moved only in the axial direction with respect to the high-pressure casing to the inside of the low-pressure casing.

5. The bundle movement method according to claim 3, further comprising

disposing a height adjustment jig, the height adjustment jig forming an adjustment surface with respect to the low-pressure casing, a position of the adjustment surface in the vertical direction coinciding with a position of an outside surface of the high-pressure bundle disposed in the high-pressure casing in the vertical direction, wherein

in the moving the high-pressure bundle, the high-pressure bundle is moved on the height adjustment jig.

6. The bundle movement method according to claim 3, wherein

in the moving the high-pressure bundle, the high-pressure bundle is moved in a state in which a central shaft of the high-pressure casing and a central shaft of the low-pressure casing are disposed at positions that coincide with the axial line when viewed from the axial direction.