Embodiments of the disclosure relate generally to gas turbine engines and more particularly relate to systems and methods for reducing or limiting one or more flows between a hot gas path and a wheel space of a turbine.
A gas turbine engine typically includes a compressor, a combustor, and a turbine. The efficiency of the turbine depends in part on the amount of cooling air flow from the compressor that is used to cool components in the hot gas path in the turbine section. The cooling air flow may be introduced into the wheel space of the turbine to limit high-temperature gases from entering into the wheel space. Excess ingestion flow of the hot gasses into the wheel space may increase the wheel space temperature beyond material capabilities, resulting in materials potentially exceeding temperature limits, which may contribute to rotor creep and/or rupture. On the other hand, excess cooling air and/or purge flow to the wheel space to prevent hot gas ingestion may decrease turbine efficiency since the cooling air flow may not be available to the entire turbine for work production.
Some or all of the above needs and/or problems may be addressed by certain embodiments of the disclosure. According to one embodiment, there is disclosed a turbine assembly. The turbine assembly may include a rotor with at least one bucket extending radially therefrom. The turbine assembly also may include a stator assembly having at least one stationary nozzle vane positioned adjacent to the at least one bucket. Moreover, the turbine assembly may include a seal assembly. The seal assembly may include a first flange extending from the at least one bucket in a substantially axial direction. The seal assembly also may include a second flange extending from the stator assembly in a substantially axial direction opposite the first flange. The second flange may include at least one protuberance projecting towards the first flange.
According to another embodiment, there is disclosed a turbine system. The system may include a compressor. The system also may include a combustion system in communication with the compressor. Moreover, the system may include a turbine in communication with the combustion system. The turbine may include a rotor having at least one bucket extending radially therefrom. The turbine also may include a stator assembly having at least one stationary nozzle vane positioned adjacent to the at least one bucket. Further, the turbine may include a seal assembly. The seal assembly may include a first flange extending from the at least one bucket in a substantially axial direction. The seal assembly also may include a second flange extending from the stator assembly in a substantially axial direction opposite the first flange. The second flange may include at least one protuberance projecting towards the first flange.
Further, according to another embodiment, there is disclosed a method to reduce or limit a flow to a wheel space and a hot gas path of a turbine. The method may include positioning a first flange about at least one bucket extending radially from a rotor. Moreover, the method may include positioning a second flange about a stator assembly positioned adjacent to the at least one bucket. The first flange and the second flange may be radially spaced apart to at least partially form a seal assembly. Further, the method may include reducing the flow to the wheel space and the hot gas path of the turbine with at least one protuberance projecting from the second flange towards the first flange.
Other embodiments, aspects, and features of the invention will become apparent to those skilled in the art from the following detailed description, the accompanying drawings, and the appended claims.
Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale.
Illustrative embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments are shown. The disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout.
The gas turbine engine 10 may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine 10 may be anyone of a number of different gas turbine engines such as those offered by General Electric Company of Schenectady, N.Y. and the like. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.
A stationary outer casing 60 may be disposed about the buckets 54 to define a hot gas passage through the turbine 40 for the flow of combustion gases 35. In addition, a number of stator assemblies 62 may be positioned adjacent to the buckets 54. For example, the stator assemblies 62 may be positioned upstream and/or downstream of each bucket 54. Each of the stator assemblies 62 may include a stationary nozzle vane 64. A wheel space 66 may be formed between each stator assembly 62 and bucket 54.
A seal assembly 68 may be positioned between each stator assembly 62 and bucket 54. The seal assembly 68 may prevent, reduced, and/or limit the flow of combustion gases 35 from entering the wheel space 66. Further, the seal assembly 68 may reduce the amount of purge air and/or cooling air needed to limit hot gases from entering the wheel space 66.
The seal assembly 68 may include a first flange 70 extending from the bucket 54 in a substantially axial direction. In some instances, the first flange 70 may be an angel wing seal. The first flange 70 may extend axially from the upstream and/or downstream surfaces of the shank portion 56 of the bucket 54. In some instances, the first flange 70 may terminate at a radially outwardly extending tip 72, which may include teeth or fins. In other instances, the radially outwardly extending tip 72 may be omitted.
The seal assembly also may include a second flange 74 extending from the stator assembly 62 in a substantially axial direction opposite the first flange 70. In some instances, the second flange 74 may be a discourager seal. Any number of discourager seals may be used herein. The second flange 74 may extend axially from the upstream and/or downstream surfaces of the stator assembly 62. In some instances, the second flange 74 may be positioned radially outward of the first flange 70. For example, the second flange 74 may be radially spaced apart from the first flange 70 so as to form a gap therebetween. Other components and other configurations may be used herein.
The protuberances extending from the second flange may prevent, reduced, and/or limit the flow of combustion gases 35 from entering the wheel space 66. Further, the protuberances extending from the second flange may prevent, reduced, and/or limit purge air and/or cooling air from entering the hot gas passage. The second flange may include multiple protuberances projecting in various directions. For example, the second flange may include one or more protuberances disposed about the distal end of the second flange, one or more protuberances disposed between the distal end of the second flange and the stator assembly, one or more protuberances projecting from the distal end of the second flange in the axial direction opposite the first flange, and/or a combination thereof.
Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. For example, the various embodiments described in