The present invention relates to an industrial gas turbine engine comprising compressor apparatus and a power turbine receiving cooling fluid from the compressor apparatus.
An industrial gas turbine engine is known comprising compressor apparatus and a power turbine coupled to a shaft of a generator. The power turbine may comprise a rotatable support shaft and a disk overhung on the support shaft. A plurality of blades are coupled to the disk. The disk is believed to be formed from an expensive high-alloy-content material having high temperature capabilities.
In accordance with a first aspect of the present invention, a power turbine receiving cooling fluid from compressor apparatus is provided. The turbine comprises: fixed housing structure; a support shaft rotatably supported in the housing structure; at least one disk overhung on the support shaft and coupled to the support shaft so as to rotate with the support shaft; and cooling fluid structure. The at least one disk is formed from a low-alloy-content steel. The cooling fluid supply structure extends through the support shaft and the at least one disk so as to supply cooling fluid to the at least one disk.
The at least one disk may comprise first and second disks overhung on the support shaft and coupled to the support shaft so as to rotate with the support shaft. The first and second disks may be formed from a low-alloy-content steel, such as AISI 4340 steel.
A plurality of circumferentially spaced apart bolts may be provided for coupling the first and second disks to the support shaft.
The cooling fluid supply structure may comprise: at least one first convey conduit extending to the fixed housing structure for providing cooling fluid from a first stage of the compressor apparatus to the fixed housing structure; a first plenum formed between the fixed housing structure and the support shaft; at least one first supply passage in the fixed housing structure through which the first stage cooling fluid passes to the first plenum; and first delivery structure formed in the support shaft and the first and second disks so as to provide the first stage cooling fluid to at least one of the first and second disks.
The first plenum, in the illustrated embodiment, extends circumferentially about 360 degrees.
The first delivery structure may comprise a plurality of circumferentially spaced apart delivery passages extending from the first plenum through the support shaft, the second disk and the first disk to a first outer surface of the first disk for providing the first stage cooling fluid to the first outer surface of the first disk.
First and second sealing structures may be associated with the fixed housing structure and the support shaft for sealing the first plenum. The first and second sealing structures may comprise first and second labyrinth sealing structures.
The cooling fluid supply structure may further comprise: at least one second convey conduit extending to the fixed housing structure for providing cooling fluid from a second stage of the compressor apparatus to the fixed housing structure; a second plenum formed between the fixed housing structure and the support shaft; at least one second supply passage in the fixed housing structure through which the second stage cooling fluid passes to the second plenum; and second delivery structure formed in the support shaft and the first and second disks so as to provide the second stage cooling fluid to at least one of the first and second disks.
In the illustrated embodiment, the second plenum extends circumferentially about 360 degrees.
The second delivery structure may comprise: at least one first delivery passageway extending from the second plenum for providing a portion of the second stage cooling fluid to a first outer cavity between the first and second disks; and at least one second delivery passageway extending from the second plenum for providing a portion of the second cooling fluid to a first inner cavity between the first and second disks.
The second delivery structure may further comprise at least one third delivery passageway extending from the second plenum for providing a portion of the second stage cooling fluid to a second inner cavity between the second disk and the support shaft.
The second delivery structure may further comprise: at least one first exit passageway extending between the first inner cavity and the first outer cavity so as to provide a path for cooling fluid in the first inner cavity to travel to the first outer cavity; and at least one second exit passageway extending between the second inner cavity to the first outer cavity so as to provide a path for cooling fluid in the second inner cavity to travel to the first outer cavity.
A third sealing structure may be provided between the housing structure and the support shaft. The second and third sealing structures may seal the second plenum. The third sealing structure may comprise a third labyrinth sealing structure.
In accordance with a second aspect of the present invention, a power turbine is provided for receiving cooling fluid from compressor apparatus comprising: fixed housing structure; a support shaft rotatably supported in the housing structure; and at least one disk overhung on the support shaft and coupled to the support shaft so as to rotate with the support shaft. The at least one disk may be formed from a low-alloy-content steel.
The at least one disk may comprise first and second disks overhung on the support shaft and coupled to the support shaft so as to rotate with the support shaft. The first and second disks may be formed from a low-alloy-content steel, such as AISI 4340 steel.
The combustor 16 combines a portion of the high pressure compressed air with a fuel and ignites the mixture creating combustion products defining a working gas. The working gases travel to the high pressure turbine 18, the low pressure turbine 20 and the power turbine 22. Within each turbine 18, 20 and 22 are rows of stationary vanes and rotating blades. For each row of blades, a separate disk is provided. The disks (not shown) forming part of the high pressure turbine 18 are coupled to a first rotatable shaft portion (not shown), which is coupled to the high pressure compressor 12 to drive the high pressure compressor 12. The disks (not shown) forming part of the low pressure turbine 20 are coupled to a second rotatable shaft portion (not shown), see
First and second disks 100 and 110 of the power turbine 22 are coupled to a rotatable support shaft 120, which is also coupled to the electric generator 24 so as to drive the electric generator 24, see
The power turbine 22 further comprises a fixed housing structure 130, see
The first and second disks 100 and 110 are overhung on the support shaft 120, i.e., are coupled to the support shaft 120 outside of rather than between the first and second journal bearings 122 and 124. In the illustrated embodiment, twelve bolts 140, circumferentially positioned 30 degrees apart, extend through bolt receiving bores 120A in a radially extended section 121 of the support shaft 120, bolt receiving bores 110A in the second disk 110 and bolt receiving bores 100A in the first disk 100, see
In the illustrated embodiment, the first and second disks 100 and 110 are formed from a low-alloy-content steel, such as AISI 4340 steel. As will be discussed further below, the power turbine 22 further comprises cooling fluid supply structure 200, which functions to cool the first and second disks 100 and 110, thereby allowing the disks 100 and 110 to be formed from a less expensive, low-alloy-content steel rather than a more expensive, high-alloy-content steel.
In the illustrated embodiment, the cooling fluid supply structure 200 comprises a plurality of circumferentially spaced-apart first fixed convey conduits 202, each extending to the fixed housing structure 130, see
The first convey conduits 202 provide cooling fluid from the high pressure compressor 12 to the fixed housing structure 130. A first plenum 210 is formed between the fixed housing structure 130 and the support shaft 120. A plurality of first supply passages 212 are formed in the fixed housing structure 130. Each first supply passage 212 communicates with a corresponding one of the first convey conduits 202 and the first plenum 210 and defines a path for high pressure cooling fluid or air to travel from the corresponding first convey conduit 202 to the first plenum 210, see
First and second sealing structures 213 and 214 are associated with the fixed housing structure 130 and the support shaft 120 for sealing the first plenum 210. The first and second sealing structures 213 and 214 comprise, respectfully, in the illustrated embodiment, first and second labyrinth sealing structures 213A and 214A.
The cooling fluid supply structure 200 further includes first delivery structure 220 comprising, in the illustrated embodiment, four circumferentially spaced apart delivery passages 222 extending from the first plenum 210, through the support shaft 120, the second disk 110 and the first disk 100, to the first outer surface 101A of the first disk 100, see
The cooling fluid supply structure 200 also comprises a plurality of circumferentially spaced-apart second fixed convey conduits 232, each extending to the fixed housing structure 130, see
A second plenum 240 is formed between the fixed housing structure 130 and the support shaft 120, see
A third sealing structure 216 may be provided between the fixed housing structure 130 and the support shaft 120. In the illustrated embodiment, the third sealing structure 216 may comprise a third labyrinth sealing structure 216A. The second and third sealing structures 214 and 216 seal the second plenum 240.
Second delivery structure 250 is formed in the support shaft 120 and the first and second disks 100 and 110 so as to provide the low pressure cooling air to the first and second disks 100 and 110.
The second delivery structure 250 comprises, in the illustrated embodiment, four first delivery passageways 252 extending from the second plenum 240 for providing a portion of low pressure cooling fluid to a first outer cavity 260 located between the first and second disks 100 and 110, see
The second delivery structure 250 further comprises, in the illustrated embodiment, two second delivery passageways 254 extending from the second plenum 240 for providing a portion of low pressure cooling fluid to a first inner cavity 262 located between the first and second disks 100 and 110, see
The second delivery structure 250 also comprises, in the illustrated embodiment, two third delivery passageways 256 extending from the second plenum 240 for providing a portion of the low pressure cooling fluid to a second inner cavity 264 between the second disk 110 and the support shaft 120, see
The second delivery structure 250 still further comprises two first exit passageways 258 extending between the first inner cavity 262 and the first outer cavity 260 so as to provide a path for cooling fluid in the first inner cavity 262 to travel or exit to the first outer cavity 260, see
The second delivery structure 250 also comprises two second exit passageways 259 extending between the second inner cavity 264 and the first outer cavity 260 so as to provide a path for cooling fluid in the second inner cavity 264 to travel or exit to the first outer cavity 260, see
In an alternative embodiment, it is contemplated that the second plenum 240 could be formed elsewhere such as within the first sealing structure 213.
While an embodiment of the present invention has been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.