Patent ID: 6082963
Filing Date: 2000-07-04
Classification: F01D,F02C,F05D

Abstract:
A method of operating a turbine having a rotor including axially spaced buckets carried thereby forming parts of turbine stages, an outer containment shell, an inner shell about the rotor including nozzles carried thereby forming other parts of said turbine stages and shrouds about tips of said buckets, respectively, of said stages, and a passage formed in said inner shell for flow of a thermal medium to control thermal movement of said inner shell, comprising the steps of:forming portions of said passage at least partially circumferentially about the inner shell at each axial location of the buckets of the stages, respectively;providing a passageway connecting the passage portions of said stages;disposing radially extending pins between said inner shell and said outer shell to preclude radial and circumferential movement of said inner shell relative to said outer shell;flowing the thermal medium through said passage portions and said passageway to control the temperature and thermal radial expansion and contraction of said inner shell; andsliding one of said inner shell and said outer shell relative to said pins in response to thermal expansion and contraction of said inner shell relative to said outer shell thereby to control the clearance between the bucket tips and the shroud.