Method for operating a turbine, turbine and manufacturing method

Abstract

The invention relates to a method for operating a turbomachine (100) comprising an impeller (110), a bearing (140) and a shaft (130) wherein the impeller (110) is arranged on the shaft (130) and wherein the shaft (130) is supported by the bearing (130) wherein the turbomachine (100) further comprises a dry gas seal (170) configured to seal the shaft (130) and wherein the shaft (130) is configured as a hollow shaft; operating the turbine includes treating a cryogenic fluid at a temperature of less than-180 DEG C. The invention also relates to a turbomachine and a method of manufacturing such a turbomachine.

Description

[0001] The present invention relates to a method for operating a turbine (e.g., a cryogenic turbine) having an impeller mounted on a shaft, and the present invention relates to such a turbine and a method for manufacturing such a turbine. Background Technology

[0002] Turbines can be used in various applications. For example, in cryogenic applications, where process gases are at low temperatures, such as in facilities for air separation, cryogenic turbines, such as turbine expanders and / or compressors, are commonly used. These turbines typically consist of expander impellers and / or compressor impellers mounted on a shaft.

[0003] Such turbines typically also include an inlet or inlet passage and an outlet or outlet passage. The inlet or inlet passage is configured to direct a working fluid, such as a process gas as mentioned, into the impeller, and the outlet or outlet passage is configured to direct, for example, the expanded working fluid from the impeller, for example, to the outside. While the turbine impeller and the corresponding impeller-side bearing components (possibly a housing) are subjected to very cold temperatures, the shaft, its bearings, and the corresponding bearing supports are typically subjected to ambient temperature or at least warmer temperatures; the bearings, for example, may even be warmer than ambient temperature. This can result in a significant heat input from the cold section to the warm section, depending on the specific temperature.

[0004] Dry gas seals for centrifugal compressors are known from the prior art, for example from US2018 / 0347589.

[0005] Therefore, the object of the present invention is to provide an improved turbine. Summary of the Invention

[0006] This objective is achieved by providing a method for operating a turbine, a turbine, and a method for manufacturing such a turbine, having the features of the independent claims. Embodiments of the invention are the subject of the dependent claims and the following description.

[0007] This invention relates to turbines, specifically cryogenic turbines, such as turbo compressors or turboexpanders, having impellers arranged or mounted on a shaft, and to operating such turbines. Types of turbines include, for example, centrifugal turbines and radial turbines. Such turbines include impellers, bearings, and a shaft. Furthermore, such turbines may also include impeller-side bearing components and bearing supports. The impeller is arranged on the shaft, and the impeller may be at least partially surrounded by the impeller-side bearing components. Furthermore, the shaft is supported by the bearings, and the bearings may be supported in the bearing supports and at least partially surrounded by the bearing supports.

[0008] Furthermore, such turbines typically include an inlet (or inlet passage) and an outlet (or outlet passage), the inlet (or inlet passage) being configured to guide the working fluid, for example, from an inlet opening to the impeller, and the outlet (or outlet passage) being configured to guide the working fluid from the impeller, for example, to an outlet opening. Cryogenic turbines use a working fluid (such as a gas or process gas (or fluid or process fluid)) at a cryogenic temperature (i.e., very low temperatures, such as below -100°C or even as low as -230°C or -250°C) at the expander outlet or compressor inlet. Depending on the type of turbine, such gases are compressed and / or expanded. Turbines in other applications may also use working fluids at higher temperatures.

[0009] In radial-flow turbines, for example, the impeller-side bearing components (surrounding the expansion impeller) may be connected to or formed as a single piece with the bearing support. Cooling energy can be extracted via the compressor impeller or via a generator connected to or arranged on the shaft. Such a generator may also be connected via a gearbox, for example.

[0010] Cold energy can also be extracted, for example, via a brake in such a radial-flow turbine, where the fluid expands from a high-pressure level to a low-pressure level. This expansion creates a high temperature difference between the inlet (high-pressure region) and the outlet (low-pressure region). Typical values ​​for hydrogen as the working fluid are, for example, an inlet temperature of -230°C and an outlet temperature of -245°C, resulting in very low temperatures in the expander impeller-side bearing components.

[0011] To achieve sufficient isentropic efficiency and maintain a positive temperature at the bearing level, heat intake must be minimized as much as possible.

[0012] It is now recognized that such heat input can be reduced by providing a turbine having a dry gas seal configured to seal the shaft, and the shaft being configured as a hollow shaft. Such a hollow shaft includes, for example, an interior without solid material and, for example, an enclosed space.

[0013] Hollow shafts allow for reduced cold transfer through the shaft and prevent hydrogen (or other working fluid) leakage from the high-pressure section to the low-pressure section (bearing support). This also allows for minimizing heat intake from the warm bearing support side to the low-temperature (expander) side.

[0014] Even in the event of a gas barrier failure, dry gas seals allow for a tight fit between the cryogenic components and the bearing or bearing support. Dry gas seals can be made of different types of technology, such as single or tandem types, and may or may not have carbon rings or other structures.

[0015] In this way, cryogenic fluids, such as hydrogen or other fluids, at temperatures below -180°C or even below -200°C can be processed by operating such turbines. Therefore, these cryogenic fluids are used as process fluids compressed and / or expanded by means of a turbine. Each of the hollow shaft and the dry gas seals allows for adequate isolation from these cryogenic conditions.

[0016] In one embodiment, the turbine further includes a heat insulation component disposed between the impeller and the dry gas seal. For example, the heat insulation component is configured for thermal insulation. Such a heat insulation plate may have an opening (i.e., the heat insulation plate has a ring or annular shape), wherein the shaft is arranged to protrude through the opening. One or more air gaps may be provided with a heat insulation component or a heat insulation element.

[0017] Thermal insulation positioned in front of the dry gas seal allows for maintaining a lower temperature at the dry gas level. Such insulation rings also allow for reduced cold transfer migration from the pressurized hydrogen section to the bearing or bearing support.

[0018] Bearing supports can be equipped with oil bearings, roller bearings, gas bearings or magnetic bearings; bearing supports can be formed or configured accordingly depending on the type of bearing.

[0019] This allows for the separation of the cryogenic section of the expander from its bearing support with minimal heat intake and effective sealing of the rotating shaft. For such applications, labyrinth seals or carbon rings are typically used for sealing. However, in the event of heat-sealing gas loss, the turbine must be stopped because the cryogenic gas will migrate inside the bearing support. Conversely, for such applications, using dry gas seals eliminates the need to stop the turbine even in the event of jet gas loss.

[0020] This invention also allows for reduced cold transfer through the rotating shaft. Even in the event of a gas barrier failure, the installation of the dry gas seal (DGS) allows for the prevention of hydrogen leakage from the high-pressure section to the low-pressure section (bearing bracket).

[0021] This invention is applicable to cryogenic rotating machines, such as radial cryogenic expanders connected to oil brakes or generators, as well as turbo expanders, centrifugal compressors, and axial turbines. This invention is particularly suitable for situations requiring DGS (dry gas seal) sealing technology compatible with low operating temperatures (e.g., between -200°C and -272°C).

[0022] Generally speaking, it is advantageous to operate such turbines for handling cryogenic fluids, preferably hydrogen, at temperatures below -180°C or -200°C. This applies to cryogenic gases such as hydrogen, but can also be used for other cryogenic gases such as helium or others, typically operating between -200°C and -270°C.

[0023] Further advantages and embodiments of the invention will become apparent from the description and accompanying drawings. The invention is schematically illustrated with reference to the embodiments in the drawings, and is described below with reference to the drawings. Attached Figure Description

[0024] Figure 1 A turbine according to an embodiment of the present invention is shown.

[0025] Figure 2 It shows Figure 1 The turbine section.

[0026] Figure 3 Shown in perspective Figure 1 The turbine section.

[0027] Figure 4 It shows Figure 1 The other part of the turbine.

[0028] Figure 5 A manufacturing method according to an embodiment of the present invention is shown. Detailed Implementation

[0029] Figure 1 A turbine 100 according to an embodiment of the invention is illustrated schematically. The turbine 100 (e.g., a cryogenic turbine) is configured, for example, as a compressor and an expander, i.e., both combined in one turbine.

[0030] Therefore, turbine 100 includes two impellers, impeller 110 and impeller 120, both mounted on shaft 130. Turbine 100 includes passages 112 and 114 located on the side of impeller 110, which serve as inlet and outlet passages for the working fluid to be compressed, respectively. Turbine 100 also includes passages 122 and 124 located on the side of impeller 120, which serve as inlet and outlet passages for the working fluid to be expanded, respectively. Therefore, impeller 110 is a compressor impeller, while impeller 120 is an expander impeller. The working fluid to be compressed and the working fluid to be expanded may have the same or different characteristics, such as pressure, temperature, chemical composition, etc.

[0031] It should be noted that a turbine may also have only one impeller mounted on one end of the shaft and a motor, such as a generator or alternator, mounted on the other end of the shaft.

[0032] Furthermore, the turbine 100 includes a bearing 140 for supporting the shaft 130 and, for example, an additional bearing 142. In the example shown, the bearing 140 is disposed on the side of the impeller 110, and the bearing 142 is disposed on the side of the impeller 120.

[0033] Furthermore, the turbine 100 includes an impeller-side bearing component 150 and a bearing support 154. The impeller-side bearing component 150 at least partially surrounds the impeller 110. Another impeller-side bearing component 152, for example, may at least partially surround the impeller 120. The bearing support 154 supports the bearing 140 and, for example, also supports the bearing 142. Furthermore, the bearing support 154 also at least partially surrounds the bearing 140 and, for example, at least partially surrounds the bearing 142.

[0034] exist Figure 1 Only the impeller-side bearing component 150 and the bearing support 154 are shown very schematically. Figure 2 and Figure 3 A more detailed view is shown below. Axis 130 is configured as a hollow axis; this is in Figure 1 Invisible in the middle, but in Figure 2 As can be seen in the text.

[0035] Furthermore, the turbine 100 includes a dry gas seal 170 and a heat insulation component 180, such as a heat shield. The dry gas seal 170 is configured to seal the shaft 130, that is, even in the event of a gas barrier failure, the dry gas seal allows for a tight fit between the low-temperature portion on the side of the impeller 110 and the bearing 140 or bearing support 154. Figure 2 and Figure 4 A more detailed view of the dry gas seal is shown in the figure.

[0036] A heat insulation component or heat shield 180 is arranged between the impeller 110 and the dry gas seal 170. For example, the heat shield 180 has an opening (i.e., the heat shield has a ring or annular shape), through which the shaft 130 is arranged to protrude. This type of insulation, positioned in front of the dry gas seal 170, allows a lower temperature to be maintained at the dry gas level. Such a heat shield also allows for reduced cold transfer migration from the pressurized hydrogen section to the bearing or bearing support.

[0037] Figure 2 The turbine 100 is shown in more detail; specifically, in addition to the shaft 130, impeller 110, and bearing 140, impeller-side bearing components 150 and bearing supports 154 are also shown. For better understanding, the axis of rotation R is shown.

[0038] Figure 3 The turbine 100 is shown in more detail and in perspective; specifically, the impeller-side bearing component 150 and bearing support 154 are shown. For better understanding, the axis of rotation R is also shown.

[0039] For example, such as Figure 2 and Figure 3As shown, the turbine also includes several connecting structures 160, which are, for example, rod-shaped; only one of these connecting structures 160 is in Figure 2 They are visible in cross-section, but some of their connecting structures are... Figure 3 As can be seen in the image. Specifically, these connecting structures 160 are spaced apart from each other and arranged in a ring around axis 130, as shown in... Figure 3 What can be seen in the middle (the axis itself is not in) Figure 3 (As shown in the image).

[0040] As in Figure 2 and Figure 3 As can be seen, the impeller-side bearing component 150 and the bearing support 154 are spatially spaced apart (viewed along the axis of rotation R) and connected to each other by a connecting structure 160. The impeller-side bearing component 160, the bearing support 155 and the connecting structure 160 may, for example, be formed as parts of a component made from a single piece, i.e., these parts may be provided integrally.

[0041] As in Figure 2 As can also be seen, the dry gas seal 170 is positioned around the shaft 130, inside the impeller-side bearing component 150, and arranged next to the bearing 140 and bearing support 154. The dry gas seal 170 can be configured, for example, as a cylinder that can be inserted into the impeller-side bearing component 150. Several seals (such as O-rings) can be provided to seal the cylinder against the impeller-side bearing component 150.

[0042] As in Figure 2 As can also be seen, the heat insulation plate 180 has an opening 182, through which the shaft 130 is arranged to protrude. The heat insulation plate 180 is arranged between the impeller 110 and the dry gas seal 170 (or dry gas seal cylinder). As described above, the shaft 130 is configured as a hollow shaft, that is, the shaft includes a space 132 inside which there is no solid material.

[0043] Figure 4 The dry gas seal 170 is shown in more detail. In addition to the dry gas seal 170, [the following is also shown]... Figure 4 A portion of the shaft 130 at the lower end and in Figure 4 A portion of the impeller-side bearing component 154 in the upper part. The dry gas seal 170 has two parts: a part 172 that rotates with the shaft 130 and a non-rotating but fixed part 174, etc. Furthermore, three channels A, B, and C for gas injection and / or connection are shown. Gas flow is indicated by arrows. These channels A, B, and C are located within the dry gas seal 170 itself and within the impeller-side bearing component 154.

[0044] Channel A is used to inject clean and dry process gases, such as cryogenic process gases like hydrogen, which are processed by a turbine. This cryogenic process gas is supplied from the side of impeller 110. Channel C is used to inject separation gases, such as nitrogen. Channel B is a connection to the flare or safety zone and is used for mixing the separation gas and process gas. The advantage of dry gas seals is that leakage from the cold process gas to the flare is very small compared to other types of dynamic seals. Most of the flow to the flare comes from the separation gas.

[0045] This type of dry gas seal is a single arrangement with a three-stage seal, allowing for a sufficient seal. It should be noted that a single dry gas seal is sometimes insufficient for hydrogen, but can be used, for example, in cases with specific rotor dynamic issues requiring protection. Other types of dry gas seals can be used, as mentioned above.

[0046] When operating such turbines at temperatures below -180°C, dry gas seals and / or hollow shafts reduce heat intake.

[0047] Figure 5 A manufacturing method according to an embodiment of the present invention is illustrated with the aid of a flowchart. This method is used to manufacture, for example, […]. Figures 1 to 4 The turbine shown is an example of a turbine that includes an impeller, bearings, and a shaft. The impeller is mounted on the shaft, and the shaft is supported by the bearings.

[0048] The method includes, in step 500, setting a dry gas seal onto the shaft. For example, this can be in the form of a cylinder. In step 510, setting the shaft to a hollow shaft.

[0049] In step 520, a heat insulation component, specifically a heat insulation plate, may be provided. The heat insulation component is arranged between the impeller and the dry gas seal. It should be noted that each step 500, 510, and 520 can be used independently of the other steps.

Claims

1. A method for operating a turbine (100), the turbine comprising an impeller (110), a bearing (140), and a shaft (130), wherein the impeller (110) is disposed on the shaft (130), and wherein the shaft (130) is supported by the bearing (130). The turbine (100) further includes a dry gas seal (170) configured to seal the shaft (130), and The shaft (130) is configured as a hollow shaft. Operating the turbine includes processing cryogenic fluids at temperatures below -180°C.

2. The method according to claim 1, wherein the turbine (100) further comprises a heat insulation component (180), specifically a heat insulation plate, wherein the heat insulation component is disposed between the impeller (110) and the dry gas seal (170).

3. The method according to claim 2, wherein the heat insulation member (180) is configured as a heat insulation plate having an opening (182), wherein the shaft (130) is arranged to protrude through the opening.

4. The method according to any one of the preceding claims, wherein the turbine (100) further comprises an impeller-side bearing component (150) and a bearing support (154). The impeller (110) is at least partially surrounded by the impeller-side bearing component (150), and The bearing (140) is supported in the bearing bracket (154) and is at least partially surrounded by the bearing bracket.

5. The method according to claim 4, wherein the impeller-side bearing component (150) and the bearing support (154) are connected to each other or formed as a single piece.

6. The method according to any one of the preceding claims, wherein the turbine (100) is configured as a cryogenic turbine.

7. The method according to any one of the preceding claims, wherein the turbine (100) is configured as at least one of: a centrifugal turbine, a radial turbine.

8. The method according to any one of the preceding claims, wherein the turbine (100) is configured as at least one of: an expander, a compressor.

9. The method according to any one of the preceding claims, wherein the bearing (140) is configured as one of: an oil bearing, a roller bearing, a gas bearing, or a magnetic bearing.

10. The method according to any one of the preceding claims, wherein the method is used to process hydrogen as the cryogenic fluid.

11. A turbine (100) comprising an impeller (110), a bearing (140), and a shaft (130), wherein the impeller (110) is disposed on the shaft (130), and wherein the shaft (130) is supported by the bearing (130). The turbine (100) further includes a dry gas seal (170) configured to seal the shaft (130), and The shaft (130) is configured as a hollow shaft. The turbine is configured to handle cryogenic fluids at temperatures below -180°C.

12. A method for manufacturing a turbine, the turbine comprising an impeller, a bearing, and a shaft, wherein the impeller is disposed on the shaft, and wherein the shaft is supported by the bearing. The method includes: A (500) dry gas seal is provided to seal the shaft, and The shaft (510) is configured as a hollow shaft. The turbine is configured to handle cryogenic fluids at temperatures below -180°C.

13. The method according to claim 12, further comprising: A heat insulation component (520), specifically a heat insulation plate, is provided and arranged between the impeller and the dry gas seal.

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