Turbomachine with a system for cooling the downstream side of an impeller of a centrifugal compressor

摘要

The system has a labyrinth seal (76) for intake of a fraction of a ventilating air flow of a turbine on an air injecting unit (36) of the turbine. An annular cylindrical passage (75) and a cylindrical sheet (94) guide the drawn ventilating air till neighborhood of a downstream face (40) of an impeller (18) of a centrifugal compressor (14). The cylindrical passage is formed around a shaft (20) of the compressor between the injecting unit and the downstream face.