AIR-COOLED TURBINE ROTOR SHROUD WITH RESTRAINTS

摘要

AIR-COOLED TURBINE ROTOR SHROUD WITH RESTRAINTS A stationary air-cooled shroud or cylinder forming a portion of a turbine assembly includes an inner ring having a matrix of grooves formed therein, and an outer restraining ring covering the matrix so as to form a labyrinth of passageways for the flow of cooling air therethrough. A suspension ring cooperates with the inner ring and the restraint ring to define an entry flow path for the cooling air and also a plenum chamber having an auxiliary outlet to provide film cooling air to the clearance spacing between the inner ring and the rotor blade tips. The flow of cool air through the labyrinth is operative to reduce the level and gradient of the metal temperatures in the shroud in order to obtain improved turbine blade tip clearance control.