Turbine seal system

Abstract

A system includes a multi-stage turbine. The multi-stage turbine includes a first turbine stage including a first wheel having a plurality of first blade segments spaced circumferentially about the first wheel, a second turbine stage including a second wheel having a plurality of second blade segments spaced circumferentially about the second wheel, and an interstage seal extending axially between the first and second turbine stages. The interstage seal is configured to be installed or removed while the first and second wheels remain in place in the respective first and second turbine stages.

1 . A system, comprising:
 a multi-stage turbine, comprising:
 a first turbine stage comprising a first wheel having a plurality of first blade segments spaced circumferentially about the first wheel; 
 a second turbine stage comprising a second wheel having a plurality of second blade segments spaced circumferentially about the second wheel; and 
 an interstage seal extending axially between the first and second turbine stages, wherein the interstage seal is configured to be installed or removed while the first and second wheels remain in place in the respective first and second turbine stages. 
   
     
     
         2 . The system of  claim 1 , wherein each of the plurality of first blade segments is coupled to the first wheel using a plurality of first mounts, and each of the plurality of second blade segments is coupled to the second wheel using a plurality of second mounts. 
     
     
         3 . The system of  claim 2 , wherein each first mount comprises a first slot in the first wheel and a first tab in one of the first plurality of blade segments, and each second mount compromises a second slot in the second wheel and a second tab in one of the second plurality of blade segments. 
     
     
         4 . The system of  claim 1 , wherein the interstage seal is configured to pivot toward an axial axis of the multi-stage turbine during installation of the interstage seal, and the interstage seal is configured to pivot away from the axial axis of the multi-stage turbine during removal of the interstage seal. 
     
     
         5 . The system of  claim 1 , wherein the interstage seal comprises an inclined support rib at an angle from an inner bridge portion of the interstage seal, wherein the inclined support rib enables the interstage seal to pivot toward and away from an axial axis of the multi-stage turbine. 
     
     
         6 . The system of  claim 5 , wherein the interstage seal comprises a second recessed portion adjacent to the inclined support rib, the second recessed portion is configured to receive a second portion of the second wheel to enable pivotal motion of the interstage seal toward and away from the axial axis, and a first recessed portion of the interstage seal is configured to receive a first portion of the first wheel while the interstage seal is moved along the axial axis toward the first turbine stage. 
     
     
         7 . The system of  claim 5 , wherein the angle is less than approximately 75 degrees. 
     
     
         8 . The system of  claim 1 , wherein the interstage seal comprises a first support feature configured to engage with a second support feature disposed on one or more of the plurality of first blade segments or the plurality of second blade segments to block radial movement of the interstage seal toward an axial axis of the multi-stage turbine during installation or removal of the interstage seal, and to block circumferential movement of the interstage seal about the axial axis during operation of the multi-stage turbine. 
     
     
         9 . The system of  claim 8 , wherein the first support feature comprises a slot and the second support feature comprises a tab. 
     
     
         10 . The system of  claim 1 , wherein the interstage seal comprises an axial end portion configured to engage a wheel rim of the first wheel or the second wheel in a radial direction during operation of the multi-stage turbine. 
     
     
         11 . The system of  claim 1 , wherein the interstage seal comprises a centrifugal seal configured to move toward the first turbine stage or the second turbine stage to block radial leakage when radial centrifugal forces are generated during operation of the multi-stage turbine. 
     
     
         12 . The system of  claim 1 , wherein the interstage seal comprises one or more seal teeth configured to block interstage axial leakage between the first turbine stage and the second turbine stage. 
     
     
         13 . The system of  claim 1 , wherein the interstage seal comprises one or more cooling passages configured to direct a cooling fluid flow toward the plurality of first blade segments or the plurality of second blade segments. 
     
     
         14 . The system of  claim 1 , comprising an interstage seal assembly disposed between the first and second turbine stages, wherein the interstage seal assembly comprises a plurality of interstage seals. 
     
     
         15 . A system, comprising:
 an interstage turbine seal configured to mount axially between first and second turbine stages of a multi-stage turbine, wherein the interstage turbine seal comprises an inclined support rib configured to enable the interstage turbine seal to pivot toward and away from an axial axis of the multi-stage turbine without removal of a first wheel of the first turbine stage and a second wheel of the second turbine stage.   
     
     
         16 . The system of  claim 15 , wherein the inclined support rib is oriented at an angle from an inner bridge portion of the interstage turbine seal, wherein the inclined support rib enables the interstage turbine seal to pivot toward and away from the axial axis of the multi-stage turbine. 
     
     
         17 . The system of  claim 16 , wherein the interstage turbine seal comprises a second recessed portion adjacent to the inclined support rib, the second recessed portion is configured to receive a second portion of the second wheel to enable pivotal motion of the interstage turbine seal toward and away from the axial axis, and a first recessed portion of the interstage turbine seal is configured to receive a first portion of the first wheel while the interstage turbine seal is moved along the axial axis toward the first turbine stage. 
     
     
         18 . The system of  claim 15 , wherein the interstage turbine seal comprises a first support feature configured to engage with a second support feature disposed on a portion of a blade segment coupled to the second wheel to block radial movement of the interstage turbine seal toward the axial axis of the multi-stage turbine during installation or removal of the interstage turbine seal, and to block circumferential movement of the interstage turbine seal about the axial axis during operation of the multi-stage turbine. 
     
     
         19 . A method, comprising:
 positioning a first recessed portion of an interstage seal about a first wheel rim of a turbomachine;   pivoting a second recessed portion of the interstage seal toward an axial axis of the turbomachine; and   moving the interstage seal along the axial axis toward a second wheel rim of the turbomachine to position the second recessed portion about the second wheel rim.   
     
     
         20 . The method of  claim 19 , comprising engaging a first support feature disposed near the first recessed portion of the interstage seal with a second support feature disposed on a portion of a blade segment coupled to the first wheel rim to block radial movement of the interstage seal toward the axial axis of the turbomachine during installation or removal of the interstage seal, and to block circumferential movement of the interstage seal about the axial axis during operation of the turbomachine.