A Rotor Blade Cooling improvement for Heavy Duty Gas Turbine Using Steam and Mixed Steam/Air Cooling

This paper proposes a theoretical study of steam cooling application for a typical rotor blade cooling system of heavy duty gas turbine. The steam cooling introduction is evaluated using open and closed loop configurations; the possible interaction of steam and air cooling is also studied; the simulation is realized with a family of modular codes developed by authors. The study is conducted with the characteristic cooling parameters (efficiency, effectiveness) analysis and by the evaluation of blade temperature distribution. The results show the possibility of a mass coolant reduction and/or, a maximum cycle temperature increase with the same cooling system used for standard air cooling. The best results are obtained with an innovative closed-open/steam-air cooling system.