WO2024084768A1

WO2024084768A1 - Expansion turbine

Info

Publication number: WO2024084768A1
Application number: PCT/JP2023/027525
Authority: WO
Inventors: 利光足立; 俊博小宮; 伸吾河原; 直也荻山
Original assignee: 川崎重工業株式会社
Priority date: 2022-10-21
Filing date: 2023-07-27
Publication date: 2024-04-25
Also published as: JP2024061078A

Abstract

An expansion turbine according to an embodiment of the present disclosure is attached to a cold box and comprises: a turbine rotor that expands a cooling gas and lowers the temperature of the cooling gas; a brake mechanism that is coupled to the turbine rotor with a main shaft therebetween; a turbine casing that accommodates the turbine rotor and includes a cooling gas supply flow path which supplies the cooling gas to the turbine rotor; a housing that accommodates at least part of the brake mechanism, is detachably attached to the turbine casing, and covers an area of the turbine casing that includes the cooling gas supply flow path from the outside of the cold box; and a strainer that is located within the cooling gas supply flow path.

Description

Expansion Turbine

This disclosure relates to an expansion turbine.

The following Patent Document 1 discloses an expansion turbine that expands compressed hydrogen refrigerant and reduces the temperature of the hydrogen refrigerant. This expansion turbine is installed in a cold box that is maintained at an extremely low temperature.

JP 2020-24067 A

In order to prevent foreign objects from entering the turbine rotor of the expansion turbine, it is possible to install a strainer upstream of the expansion turbine. However, in this case, the strainer cannot be accessed from outside the cold box, and therefore cannot be accessed during maintenance of the expansion turbine, etc.

The present disclosure therefore aims to provide an expansion turbine that allows access to the strainer from outside the cold box.

The expansion turbine according to one embodiment of the present disclosure is an expansion turbine attached to a cold box, and includes a turbine rotor that expands a cooling gas to reduce the temperature of the cooling gas, a brake mechanism connected to the turbine rotor via a main shaft, a turbine casing that houses the turbine rotor and includes a cooling gas supply passage that supplies the cooling gas to the turbine rotor, a housing that houses at least a portion of the brake mechanism and is detachably attached to the turbine casing, covering an area of the turbine casing that includes the cooling gas supply passage from the outside of the cold box, and a strainer located within the cooling gas supply passage.

This configuration allows access to the strainer from outside the cold box.

FIG. 1 is a cross-sectional view of an expansion turbine. FIG. 2 is a view of the strainer as seen from inside the cold box. FIG. 3 is a cross-sectional view of an expansion turbine according to a modified example. FIG. 4 is a cross-sectional view of an expansion turbine according to another modified example.

The expansion turbine 100 according to the embodiment will be described below. FIG. 1 is a cross-sectional view of the expansion turbine 100. The expansion turbine 100 according to this embodiment is a device that cools a cooling gas. The cooling gas in this embodiment is hydrogen gas, which is used to generate liquid hydrogen. However, the cooling gas is not limited to hydrogen gas.

The expansion turbine 100 according to this embodiment is attached to the outer wall 102 of a cold box 101, the inside of which is maintained at an extremely low temperature. In FIG. 1, the side below the outer wall 102 of the cold box 101 on the paper is the inside of the cold box 101, and the side above the outer wall 102 on the paper is the outside of the cold box 101. In the following, the side closer to the center of the inside of the cold box 101 (the lower side of the paper in FIG. 1) is referred to as the "inside of the cold box," and the side farther from the center of the inside of the cold box 101 (the upper side of the paper in FIG. 1) is referred to as the "outside of the cold box."

As shown in FIG. 1, the expansion turbine 100 according to this embodiment includes a turbine rotor 10, a brake mechanism 11, a turbine casing 12 that houses the turbine rotor 10, a housing 13 that houses the brake mechanism 11, a strainer 14, a retainer 15 that holds the strainer 14, and an intermediate member 16 that contacts the strainer 14. Below, these components will be described in order.

The turbine rotor 10 is a part that expands the cooling gas to lower its temperature. In this embodiment, the turbine rotor 10 is a centrifugal turbine. The turbine rotor 10 rotates around a central axis 90 shown in FIG. 1. The cooling gas flows into the turbine rotor 10 in the radial direction (perpendicular to the central axis 90) and flows out in the axial direction (the extension direction of the central axis 90). As the cooling gas passes through the turbine rotor 10, the turbine rotor 10 is driven to rotate by the energy of the cooling gas.

The brake mechanism 11 is connected to the turbine rotor 10 via the main shaft 20, and is a part that absorbs the energy of the turbine rotor 10. Specifically, the brake mechanism 11 is a brake impeller that absorbs the energy of the turbine rotor 10 by increasing the pressure of the brake gas. The brake impeller, which is the brake mechanism 11 of this embodiment, is a centrifugal compressor that rotates around the central axis 90, just like the turbine rotor 10. The brake gas flows into the brake impeller from the axial direction and flows out in the radial direction. The brake gas may be the same gas as the cooling gas, or a different gas may be used. The brake mechanism 11 is not limited to a brake impeller, and may be, for example, a generator, etc.

The turbine casing 12 is the part that houses the turbine rotor 10. The turbine casing 12 is fixed to the outer wall 102 of the cold box 101 by welding. The turbine casing 12 includes a cooling gas inlet passage 21 that takes in cooling gas, a cooling gas supply passage 22 that supplies the cooling gas taken in from the cooling gas inlet passage 21 to the turbine rotor 10, and a cooling gas discharge passage 23 that discharges the cooling gas that has passed through the turbine rotor 10 downstream.

Of the above-mentioned flow paths, the cooling gas inlet flow path 21 extends perpendicularly to the central axis 90. The cooling gas supply flow path 22 is cylindrical and centered on the central axis 90, and extends along the direction of extension of the central axis 90. The cooling gas exhaust flow path 23 is located on the central axis 90 and radially inside the cooling gas supply flow path 22. As shown by the black arrow in FIG. 1, the cooling gas that has passed through the cooling gas inlet flow path 21 flows through the cooling gas supply flow path 22 toward the outside of the cold box, and then flows into the turbine rotor 10 through the nozzle vane 24. The cooling gas that has flowed out from the turbine rotor 10 flows through the cooling gas exhaust flow path 23 toward the inside of the cold box.

The housing 13 is a portion that houses at least a portion of the brake mechanism 11. The housing 13 is removably attached to the turbine casing 12. Furthermore, the housing 13 is located outside the cold box relative to the turbine casing 12, and covers an area including the cooling gas supply passage 22 of the turbine casing 12 from the outside of the cold box. As shown by the black arrow in FIG. 1, brake gas flows into the housing 13, and the brake gas flows through the brake impeller, which is the brake mechanism 11, toward equipment downstream of the expansion turbine 100.

The strainer 14 is a part that removes foreign matter from the cooling gas. In this embodiment, the strainer 14 is located within the expansion turbine 100, not upstream of the expansion turbine 100. Specifically, the strainer 14 is located within the cooling gas supply passage 22 of the turbine casing 12. The strainer 14 in this embodiment includes a cylindrical, mesh-shaped strainer body 31, an annular inner mounting ring 32 located inside the cold box relative to the strainer body 31, and an annular outer mounting ring 33 located outside the cold box relative to the strainer body 31.

The strainer 14 is removably attached to the turbine casing 12. In this embodiment, the inner mounting ring 32 of the strainer 14 is inserted into a cylindrical mounting groove 34 located near the inner end of the cold box of the cooling gas supply passage 22. The outer mounting ring 33 of the strainer 14 is removably held by a retainer 15, which will be described later. The strainer 14 of this embodiment can remove foreign matter from the cooling gas as the cooling gas flows from the radial outside to the radial inside of the strainer 14.

Here, FIG. 2 is a view of the strainer 14 as seen from inside the cold box. As shown in FIG. 2, the inner mounting ring 32 has an anti-rotation key 35 that protrudes radially inward. This anti-rotation key 35 is inserted into a key groove formed in the mounting groove 34 and engages with the turbine casing 12. If the cross section of the strainer 14 is circular as in this embodiment, there is a risk that the strainer 14 will rotate around the central axis 90. However, as described above, if the strainer 14 has an anti-rotation key 35 that engages with the turbine casing 12, the strainer 14 can be prevented from rotating. The anti-rotation key 35 may be formed to protrude radially outward from the inner mounting ring 32. The outer mounting ring 33 may also have an anti-rotation key 35. In this case, a key groove may be formed in the retainer 15.

The retainer 15 is a part that holds the strainer 14. In this embodiment, the retainer 15 is cylindrical and holds the outer mounting ring 33 of the strainer 14. Furthermore, the retainer 15 is removably attached to the turbine casing 12. Therefore, according to this embodiment, the strainer 14 can be removed from the turbine casing 12 by removing the housing 13 from the turbine casing 12 and then removing the retainer 15 from the turbine casing 12. In other words, the strainer 14 can be accessed from outside the cold box. As a result, while the cold box 101 is usually held in a vacuum state, according to this embodiment, the strainer 14 can be removed without releasing the vacuum state of the cold box 101.

The intermediate member 16 is a member located between the strainer 14 and the turbine casing 12. In this embodiment, the intermediate member 16 is located between the inner mounting ring 32 and the mounting groove 34, and between the outer mounting ring 33 and the retainer 15. The intermediate member 16 is annular and formed to be elastically deformable. In this manner, in this embodiment, since the strainer 14 is attached to the turbine casing 12 via the intermediate member 16, even if the strainer 14 deforms due to a temperature change, the intermediate member 16 follows the deformation, and it is possible to prevent the strainer 14 from falling off the turbine casing 12.

(Modification)
Although the strainer 14 is cylindrical in shape in the above description, the shape of the strainer 14 is not limited to this. For example, as shown in Fig. 3, the strainer 14 may be annular and configured to remove foreign matter from the cooling gas passing through the strainer 14 in the axial direction. Also, as shown in Fig. 4, the strainer 14 may be dome-shaped and configured to remove foreign matter from the cooling gas flowing from the cooling gas inlet passage 21 to the cooling gas supply passage 22. Even in these configurations, the strainer 14 is located inside the cooling gas supply passage 22. Therefore, if the housing 13 is removed from the turbine casing 12, the strainer 14 can be accessed from outside the cold box.

(summary)
The first item disclosed in this specification is an expansion turbine attached to a cold box, comprising: a turbine rotor that expands a cooling gas to reduce the temperature of the cooling gas; a brake mechanism connected to the turbine rotor via a main shaft; a turbine casing that houses the turbine rotor and includes a cooling gas supply passage that supplies the cooling gas to the turbine rotor; a housing that houses at least a portion of the brake mechanism, is detachably attached to the turbine casing, and covers the cooling gas supply passage from the outside of the cold box; and a strainer located within the cooling gas supply passage.

With this configuration, the strainer can be accessed from outside the cold box by removing the housing from the turbine casing.

The second item disclosed in this specification is the expansion turbine described in the first item, further comprising a retainer that is removably attached to the turbine casing and holds the strainer, and the strainer is attached to the turbine casing via the retainer.

With this configuration, the strainer can be easily removed from the turbine casing by removing the retainer from the turbine casing.

The third item disclosed in this specification is the expansion turbine described in the first or second item, further comprising an elastically deformable intermediate member located between the strainer and the turbine casing, and the strainer is attached to the turbine casing via the intermediate member.

With this configuration, if the strainer is deformed due to temperature changes, the intermediate member follows the deformation, preventing the strainer from falling off the turbine casing.

The fourth item disclosed in this specification is an expansion turbine described in any one of the first to third items, in which the strainer has a circular cross section and includes an anti-rotation key that protrudes radially and engages with the turbine casing.

This configuration prevents the strainer from rotating.

REFERENCE SIGNS LIST 10 turbine rotor 11 brake mechanism 12 turbine casing 13 housing 14 strainer 15 retainer 16 intermediate member 20 main shaft 22 cooling gas supply passage 35 anti-rotation key 100 expansion turbine 101 cold box

Claims

An expansion turbine mounted in a cold box,
a turbine rotor that expands the cooling gas to reduce a temperature of the cooling gas;
a brake mechanism connected to the turbine rotor via a main shaft;
a turbine casing that houses the turbine rotor and includes a cooling gas supply passage that supplies the cooling gas to the turbine rotor;
a housing that accommodates at least a portion of the brake mechanism, is detachably attached to the turbine casing, and covers an area of the turbine casing that includes the cooling gas supply passage from outside a cold box;
a strainer located in the cooling gas supply passage.
The expansion turbine of claim 1, further comprising a retainer that is removably attached to the turbine casing and holds the strainer, and the strainer is attached to the turbine casing via the retainer.
The expansion turbine of claim 1, further comprising an elastically deformable intermediate member located between the strainer and the turbine casing, the strainer being attached to the turbine casing via the intermediate member.
2. The expansion turbine of claim 1, wherein the strainer is circular in cross section and includes a radially projecting anti-rotation key that locks into the turbine casing.