Apparatus for cooling an axial-flow gas turbine

Abstract

An apparatus for cooling an axial-flow gas turbine of the type comprising a multi-stage turbine (1) which drives a compressor (10) arranged on a common shaft (13), involves means for removing leakage air from the space surrounding the portion of the shaft between the turbine and the compressor. In such an installation, the portion of the shaft between the turbine (1) and the compressor (10) is shaped as a drum (14) and is surrounded by a drum cover (15), which forms an annular duct (20). A labyrinth seal (21) sealing against the drum cover (15) is disposed in the annular duct (20), and the drum cover (15) together with the end face (18) of the turbine rotor (3) defines a radially directed wheel side space (19). Separate lines (22) for carrying the turbine-rotor cooling air from the compressor (10) to the end face (18) of the turbine rotor (3) are provided, and the connection between these lines (22) and the wheel side space (19) is made via at least one swirl nozzle (23). Cooling devices (24) are provided for introducing cooling air to the turbine rotor (3) and its moving-blade rings, and all the cooling air for the rotor side for the turbine (1) is extracted from the compressor (10) in the area of the compressor discharge. At least one suction device (25) for removing the leakage air and a portion of the cooling air from the annular duct is connected to the annular duct in the area of the drum labyrinth (21). The suction device (25) is connected to deliver the removed leakage air to cooling devices for the rear turbine stages.

Dependencies are inferred from the claim text.