Expansion turbine

Abstract

An expansion turbine according to one embodiment of the present disclosure is an expansion turbine attached to a cold box, the expansion turbine 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 housing that houses the turbine rotor, and that includes a cooling gas supply flow path that supplies the cooling gas to the turbine rotor; a housing that accommodates at least a part of the brake mechanism, is detachably attached to the turbine housing, and covers a region including the cooling gas supply flow path of the turbine housing from the outside of a cold box; and a filter located in the cooling gas supply flow path.

Description

Technical Field

[0001] The present disclosure relates to expansion turbines. Background Art

[0002] Patent Document 1 below discloses an expansion turbine that expands compressed refrigerant hydrogen to reduce the temperature of the refrigerant hydrogen. The expansion turbine is provided in a cold box maintained at an extremely low temperature.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-24067 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In order to prevent the inflow of foreign matter into the turbine rotor of the expansion turbine, it is considered to set a filter upstream of the expansion turbine. However, in this case, since the filter cannot be approached from the outside of the cold box, the filter cannot be approached during maintenance of the expansion turbine.

[0008] It is therefore an object of the present disclosure to provide an expansion turbine in which the filter can be accessed from outside the cold box.

[0009] Means for solving problems

[0010] An expansion turbine in one embodiment of the present invention is installed in a cold box, wherein the expansion turbine comprises: a turbine rotor, which expands cooling gas to reduce the temperature of the cooling gas; a braking mechanism, which is connected to the turbine rotor via a main shaft; a turbine casing, which accommodates the turbine rotor and includes a cooling gas supply flow path for supplying the cooling gas to the turbine rotor; an outer casing, which accommodates at least a portion of the braking mechanism and is detachably mounted on the turbine casing, the outer casing covering an area including the cooling gas supply flow path of the turbine casing from the outside of the cold box; and a filter, which is located in the cooling gas supply flow path.

[0011] Effects of the Invention

[0012] According to this structure, the filter can be approached from the outside of the cold box. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a cross-sectional view of the expansion turbine.

[0014] Figure 2 This is a picture of the filter viewed from the inside of the cold box.

[0015] Figure 3 It is a cross-sectional view of an expansion turbine according to a modified example.

[0016] Figure 4 It is a cross-sectional view of an expansion turbine according to another modified example. DETAILED DESCRIPTION

[0017] Hereinafter, the expansion turbine 100 according to the embodiment will be described. Figure 1 1 is a cross-sectional view of the expansion turbine 100. The expansion turbine 100 of this embodiment is a device for cooling a cooling gas. The cooling gas of this embodiment is hydrogen gas, and is used to generate liquid hydrogen. However, the cooling gas is not limited to hydrogen gas.

[0018] The expansion turbine 100 of this embodiment is mounted on the outer wall 102 of a cold box 101 whose interior is maintained at an extremely low temperature. Figure 1 In the figure, the inner part of the cold box 101 is closer to the outer wall 102 of the cold box 101 than the inner part of the cold box 101, and the outer part of the cold box 101 is closer to the outer wall 102 than the outer wall 102. Figure 1 The lower side of the paper) is called the "inner side of the cold box", and the side away from the inner center of the cold box 101 ( Figure 1 The upper side of the paper) is called the "outside of the cold box".

[0019] like Figure 1 As shown, the expansion turbine 100 of this embodiment includes a turbine rotor 10, a brake mechanism 11, a turbine housing 12 accommodating the turbine rotor 10, a housing 13 accommodating the brake mechanism 11, a filter 14, a retainer 15 for retaining the filter 14, and an intermediate member 16 connected to the filter 14. These components will be described in turn below.

[0020] The turbine rotor 10 is a part that expands the cooling gas to reduce the temperature of the cooling gas. The turbine rotor 10 of this embodiment is a centrifugal turbine. Figure 1 The central axis 90 shown rotates. The cooling gas flows into the turbine rotor 10 from the radial direction (the direction perpendicular to the central axis 90) and flows out in the axial direction (the extending 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.

[0021] 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 of the brake mechanism 11 of the present embodiment is a centrifugal compressor, which rotates around the central axis 90 in the same way as the turbine rotor 10. The brake gas flows into the brake impeller from the axial direction and flows out in the radial direction. In addition, as the brake gas, the same gas as the cooling gas can be used, or other gases can be used. In addition, the brake mechanism 11 is not limited to a brake impeller, and it can also be a generator, etc.

[0022] The turbine housing 12 is a portion that accommodates the turbine rotor 10. The turbine housing 12 is fixed to the outer wall 102 of the cold box 101 by welding. The turbine housing 12 includes: a cooling gas inlet flow path 21 that takes in cooling gas into the interior of the turbine housing 12; a cooling gas supply flow path 22 that supplies the cooling gas taken in from the cooling gas inlet flow path 21 to the turbine rotor 10; and a cooling gas exhaust flow path 23 that exhausts the cooling gas that has passed through the turbine rotor 10 to the downstream.

[0023] The cooling gas inlet flow path 21 of each of the above-mentioned flow paths extends perpendicularly to the central axis 90. In addition, the cooling gas supply flow path 22 is cylindrical centered on the central axis 90 and extends along the extension direction of the central axis 90. In addition, the cooling gas exhaust flow path 23 is located on the central axis 90 and is located radially inside the cooling gas supply flow path 22. Figure 1 As shown by the black arrow in FIG. 2 , the cooling gas having passed through the cooling gas inlet flow path 21 flows toward the outside of the cold box in the cooling gas supply flow path 22, and then flows into the turbine rotor 10 through the nozzle vanes 24. Then, the cooling gas flowing out of the turbine rotor 10 flows toward the inside of the cold box in the cooling gas exhaust flow path 23.

[0024] The housing 13 is a portion that accommodates at least a portion of the brake mechanism 11. The housing 13 is detachably mounted on the turbine housing 12. The housing 13 is located closer to the outside of the cold box than the turbine housing 12, and covers the area including the cooling gas supply flow path 22 of the turbine housing 12 from the outside of the cold box. Figure 1 As shown by the black arrow in FIG. 1 , the brake gas flows into the casing 13 , and the inflowing brake gas passes through the brake impeller as the brake mechanism 11 and flows toward the device downstream of the expansion turbine 100 .

[0025] The filter 14 is a part that removes foreign matter from the cooling gas. In the present embodiment, the filter 14 is not located upstream of the expansion turbine 100, but is located inside the expansion turbine 100. Specifically, the filter 14 is located in the cooling gas supply flow path 22 of the turbine housing 12. The filter 14 of the present embodiment includes: a filter body 31, which is cylindrical and has a mesh; an annular inner mounting ring 32, which is located at a position closer to the inside of the cold box than the filter body 31; and an annular outer mounting ring 33, which is located at a position closer to the outside of the cold box than the filter body 31.

[0026] The filter 14 is detachably mounted on the turbine housing 12. In the present embodiment, the inner mounting ring 32 of the filter 14 is inserted into a cylindrical mounting groove 34 located near the inner end of the cold box of the cooling gas supply flow path 22. In addition, the outer mounting ring 33 of the filter 14 is detachably held by the retainer 15 described later. The filter 14 of the present embodiment can remove foreign matter from the cooling gas when the cooling gas flows from the radial outer side to the radial inner side of the filter 14.

[0027] here, Figure 2 This is a diagram of the filter 14 viewed from the inside of the cold box. Figure 2 As shown, the inner mounting ring 32 has a rotation prevention key 35 protruding radially inward. The rotation prevention key 35 is inserted into the keyway formed in the mounting groove 34, thereby being locked to the turbine housing 12. As in the present embodiment, when the cross-section of the filter 14 is circular, the filter 14 may rotate around the central axis 90. However, as described above, if the filter 14 has a rotation prevention key 35 that is locked to the turbine housing 12, the filter 14 can be prevented from rotating. In addition, the rotation prevention key 35 can also be formed to protrude radially outward from the inner mounting ring 32. In addition, the outer mounting ring 33 can also have a rotation prevention key 35. In this case, a keyway can be formed on the retainer 15.

[0028] The retainer 15 is a portion that retains the filter 14. The retainer 15 of the present embodiment is cylindrical and retains the outer mounting ring 33 of the filter 14. In addition, the retainer 15 is detachably mounted on the turbine housing 12. Therefore, according to the present embodiment, if the housing 13 is removed from the turbine housing 12, and the retainer 15 is further removed from the turbine housing 12, the filter 14 can be removed from the turbine housing 12. That is, the filter 14 can be approached from the outside of the cold box. As a result, the cold box 101 is usually maintained in a vacuum state, but according to the present embodiment, the filter 14 can be removed without releasing the vacuum state of the cold box 101.

[0029] The intermediate component 16 is a component located between the filter 14 and the turbine housing 12. The intermediate component 16 of the present embodiment 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 component 16 is annular and is formed to be elastically deformable. Thus, in the present embodiment, the filter 14 is mounted on the turbine housing 12 via the intermediate component 16. Therefore, even if the filter 14 is deformed due to temperature changes, the intermediate component 16 will follow the deformation, and the filter 14 can be prevented from falling off from the turbine housing 12.

[0030] (Variation Example)

[0031] In the above, the case where the filter 14 is cylindrical is described, but the shape of the filter 14 is not limited to this. Figure 3 As shown in FIG. 1 , the filter 14 may also be annular and configured to remove foreign matter from the cooling gas passing through the filter 14 in the axial direction. Figure 4 As shown, the filter 14 may also be dome-shaped and configured to remove foreign matter from the cooling gas flowing from the cooling gas inlet flow path 21 into the cooling gas supply flow path 22. Even in these structures, the filter 14 is located in the cooling gas supply flow path 22. Therefore, if the housing 13 is removed from the turbine housing 12, the filter 14 can be accessed from the outside of the cold box.

[0032] (Summarize)

[0033] The first item disclosed in the present specification is an expansion turbine installed in a cold box, wherein the expansion turbine comprises: a turbine rotor, which expands the cooling gas to reduce the temperature of the cooling gas; a braking mechanism, which is connected to the turbine rotor via a main shaft; a turbine casing, which accommodates the turbine rotor and includes a cooling gas supply flow path for supplying the cooling gas to the turbine rotor; an outer casing, which accommodates at least a portion of the braking mechanism and is detachably mounted on the turbine casing, the outer casing covering the cooling gas supply flow path from the outside of the cold box; and a filter, which is located in the cooling gas supply flow path.

[0034] According to this configuration, when the casing is removed from the turbine housing, the filter can be accessed from the outside of the cold box.

[0035] A second item disclosed in the present specification is the expansion turbine according to the first item, wherein the expansion turbine further includes a retainer that is detachably mounted on the turbine housing and retains the filter, and the filter is mounted on the turbine housing via the retainer.

[0036] According to this structure, by removing the retainer from the turbine housing, the filter can be easily removed from the turbine housing.

[0037] The third item disclosed in the present specification is the expansion turbine according to the first or second item, wherein the expansion turbine further includes an elastically deformable intermediate member located between the filter and the turbine housing, and the filter is mounted on the turbine housing via the intermediate member.

[0038] According to this configuration, when the filter is deformed due to temperature change, the intermediate member follows the deformation, thereby preventing the filter from falling off the turbine housing.

[0039] A fourth item disclosed in the present specification is the expansion turbine according to any one of the first to third items, wherein the filter has a circular cross-section and includes a rotation preventing key protruding in a radial direction and locked to the turbine housing.

[0040] According to this structure, the filter can be prevented from rotating.

[0041] Description of symbols

[0042] 10: turbine rotor; 11: brake mechanism; 12: turbine housing; 13: casing; 14: filter; 15: retainer; 16: intermediate component; 20: main shaft; 22: cooling gas supply flow path; 35: rotation prevention key; 100: expansion turbine; 101: cold box.

Claims

1. An expansion turbine installed in a cold box, wherein: The expansion turbine has: a turbine rotor that expands the cooling gas to reduce the temperature of the cooling gas; a brake mechanism connected to the turbine rotor via a main shaft; a turbine housing that accommodates the turbine rotor and includes a cooling gas supply flow path that supplies the cooling gas to the turbine rotor; a housing that accommodates at least a portion of the brake mechanism and is detachably mounted on the turbine housing, the housing covering a region including the cooling gas supply flow path of the turbine housing from the outside of the cold box; and A filter is located in the cooling gas supply flow path.

2. The expansion turbine according to claim 1, wherein: The expansion turbine further includes a retainer which is detachably mounted on the turbine housing and holds the filter. The filter is mounted on the turbine housing via the retainer.

3. The expansion turbine according to claim 1, wherein: The expansion turbine also has an elastically deformable intermediate component, which is located between the filter and the turbine housing. The filter is mounted on the turbine housing via the intermediate member.

4. The expansion turbine according to claim 1, wherein: The filter has a circular cross-section and includes a rotation preventing key that protrudes in a radial direction and is locked to the turbine housing.

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