| 主权项 |
1. A gas turbine comprising:
a turbine casing; a rotor mounted for rotation within the turbine casing and comprising a rotor shaft and at least a first stage upstream rotor disc and a second stage downstream rotor disc axially displaced on the rotor shaft to form an interstage disc cavity therebetween, the rotor having a plurality of rotor blades extending radially outward from the rotor discs into a main gas flow, the second stage rotor disc positioned in a downstream direction with respect main gas flow from the first stage upstream rotor disk; a stator comprising a plurality of stator stages, a first of the stator stages extending radially inward to the interstage disc cavity from the turbine casing toward the rotor shaft, the plurality of stator stages providing multiple stator vanes axially aligned with the rotor blades in the main gas flow and terminating radially inwardly with a seal housing which provides a seal about the rotor shaft, the first of the stator stages including an attachment portion connecting the seal housing to at least one stator vane, wherein a combination, comprising the seal housing, and the first stage rotor disc, including a surface of the first stage rotor disc which faces the seal housing, and the second stage rotor disc, including a surface of the second stage rotor disc facing the seal housing, form a seal assembly about the interstage disc cavity, the seal housing including a first portion facing the surface of the first stage rotor disc and a second portion facing the first surface of the second stage rotor disc; first and second seal housing flanges each extending outward from the first portion of the seal housing, each extending toward the surface of the first stage rotor disc; inner and outer rotor flanges each extending outward from the first stage upstream rotor disk along the surface of the first stage rotor disc toward the first of the stator stages, wherein: the inner rotor flange and first seal housing flange are positioned radially inward relative to the second seal housing flange and the outer rotor flange is positioned radially outward relative to the second seal housing flange, the outer rotor flange functions as a rim seal, the inner rotor flange and the first seal housing flange extend toward one another in close proximity to limit ingress of main gas flow along the rotor shaft, wherein a portion of the interstage disc cavity between the seal housing and the surface of the first stage rotor disc which faces the seal housing includes at least first and second interconnected flow regions where (i) the first flow region is positioned radially outward with respect to the second flow region so that the first flow region must initially receive a portion of the main gas flow before that portion is received by the second flow region and (ii) the first flow region is between the outer rotor flange and the second seal housing flange and (iii) the second flow region is between the inner rotor flange and the first seal housing flange, and the first portion of the seal housing includes a cooling air inlet positioned to inject air directly into the first flow region of the disc cavity between the outer rotor flange and the second seal housing flange such that air injected directly into the first flow region must flow through the first flow region before flowing into the second flow region. |
