Method for reducing steady state rotor blade tip clearance in a land-based gas turbine to improve efficiency
AssigneeWestinghouse Electric Corp.
InventorGregory R. Gaul
Life of this patent
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Abstract
Disclosed is a method for improving the efficiency of a land-based gas turbine by controlling the blade tip clearance. The diameter of the outer gas path casing is increased during transient periods. The outer casing is heated during transient periods to increase its diameter and the associated blade tip clearance thereby allowing for a reduced cold tip clearance and and conseuently steady-state running clearance.
Claims15
A method of improving the efficiency of a gas turbine during steady state operation, said turbine having at least one blade tip and a support member disposed in relation to said blade tip to define a blade tip clearance, comprising the steps of:
- (a) providing a predetermined minimum blade tip clearance between the at least one blade tip and the support member, (b) controlling said blade tip clearance during a transient, non-steady state period of operation of the turbine such that the predetermined minimum blade tip clearance is substantially maintained during a steady state period of operation of said turbine.
A gas turbine system comprising a gas turbine having at least one blade tip, a support member having an outside diameter disposed in relation to said blade tip to define a blade tip clearance, and means for controlling said blade tip clearance during a start-up period of operation of the turbine such that a minimum blade tip clearance is provided during a steady state operation of said turbine.
Dependencies are inferred from the claim text.