Clearance control
AssigneeGeneral Electric Company
InventorsLarry D. Cline, Ambrose A. Hauser, James E. Sidenstick, Mark S. Zlatic
Life of this patent
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Abstract
A system is provided inside a turbomachine for controlling operational clearance between a turbine rotor and a surrounding turbine shroud. The system comprises a plurality of control rings, integrated into the turbine casing, that are thermally expanded and contracted to control radial positioning of the turbine shroud. Compressor air is directed through internal passages in the rings to cause the expansion and contraction. The system utilizes the pressure and temperature of compressor air, in combination with size, location, and structure of the control rings to match thermal growth of the control rings and turbine shroud to thermal growth of the turbine rotors, thereby controlling clearance.
Claims9
An improved turbomachine having a compressor section and a turbine section with turbine parts rotating in close clearance relationship within a circumferential turbine shroud structure for operation over a range of temperatures and speeds, wherein the improvement comprises:
- at least one pair of clearance control rings structurally integrated into a turbine case surrounding the turbine section, wherein said rings comprise radially extending structures that are provided with internal passages for directing a fluid through said pair of rings to control thermal growth thereof, said pair of rings being generally radially aligned with a turbine shroud, a first control ring of said pair being generally radially aligned with an upstream end of said turbine shroud with a second control ring of said pair being generally radially aligned with a downstream end of said turbine shroud;
- and
- means for causing thermal growth of said turbine shroud to respond to thermal growth of said pair of control rings for the purpose of controlling clearance between said turbine shroud and said rotating turbine parts wherein said generally aligned pair of control rings causes said turbine shroud to expand and contract radially and remain parallel to a central axis of said turbomachine.
In a method of clearance control for use in combination with a turbomachine having rotating parts surrounded by shroud structure which is coupled to a turbine case of the type having a plurality of radially extending structures each of which is provided with internal passages, comprising the step of:
- circulating a fluid through said internal passages of said radially extending structures to control thermal growth of said radially extending and shroud structures.
Dependencies are inferred from the claim text.