Abstract: The turbine blades of a gas turbine engine are individually cooled through the internal circulation of a fluid coolant by the thermosiphon principle. Each turbine blade has associated therewith a closed-loop coolant passageway which is rotatable with the turbine rotor disk and which, in one embodiment, passes through a heat exchanger borne by, and rotatable with, a rotatable lubrication duct. The blade internal coolant is placed in heat exchange relationship with engine lubrication oil within the heat exchanger. The heated lubrication oil is then placed in heat exchange relationship with the engine fuel and the fuel thus heated is burned in the combustor, thereby returning at least a portion of the heat removed from the turbine blades to the engine power cycle. The cooling system is designed for simplified blade removal and replacement and the entire turbine can be removed from the engine as a sealed unit.

Abstract: A gas turbine engine having a compressor and an air-cooled turbine is provided with a cooling system for decreasing the temperature of the turbine cooling air. A compact heat exchanger, rotatable with the compressor, receives a portion of the pressurized air which is bled from the compressor. Relatively cool engine lubrication oil is pumped through the heat exchanger into heat exchange relationship with the pressurized air, thereby cooling the air and heating the lubrication oil. The cooled air is then routed to and circulated through the turbine blades to provide improved internal cooling thereof. The heated lubrication oil is collected from the heat exchanger and routed to a second heat exchanger wherein it is placed in heat exchange relationship with engine fuel to recover the heat extracted from the compressor bleed air and to return the heat to the engine operating cycle. The cooling system is designed to contain the lubricant in the unlikely event of a leak developing in the heat exchanger.