Patent ID: 7086233
Filing Date: 2006-08-08
Classification: F01D

Abstract:
1. A method for controlling blade tip clearances comprising the steps of: (a) operating a turbine engine, the turbine engine having a compressor section, a combustor section and a turbine section, the turbine section including a rotor with discs on which a plurality of blades are attached; (b) extracting a portion of the combustion gases from the combustor section of the turbine engine; (c) combining the portion of combustion gases with a portion of the compressor exit air to form a mixture, wherein the temperature of the mixture is greater than the temperature of the compressor exit air as it exits the compressor section; (d) monitoring at least one engine operating parameter; and (e) selectively supplying the mixture to at least one stationary blade ring based on the at least one engine operating parameter, wherein at least a portion of the at least one blade ring is substantially proximate to the blades, wherein the temperature of the mixture is greater than the temperature of the at least one blade ring, wherein said mixture supplying is performed automatically by an engine controller, whereby exposure to the mixture causes thermal expansion of the blade ring such that the clearance between the tips of the blades and a neighboring stationary blade ring increases.