Application of Oxide Dispersion Strengthening Coatings for Improved Transpiration Cooling

Specifications for current 7FA-05 land-based gas turbine engines require inlet operating temperatures to be maintained at ∼1,360 °C. However, to improve overall power generation efficiency, turbine engines are being designed to operate at greater temperatures: ∼1,485 °C for the H-engine, ∼1,620 °C for the J-engine, and ∼1,700 °C for future engines. To achieve these goals, high-efficiency, near-zero emission turbine power systems depend on the advancement of thermal protection of hot sections, such as the first and second stage rotating and stationary airfoils and control of secondary flows. Current technology for protecting turbine airfoils primarily relies on the combined effects of a thermal barrier coating and convective cooling. However, simply focusing on the development of thermal barrier coatings materials and cooling technologies is insufficient to meet the thermal-mechanical demands imposed by the hot gas future with elevated turbine-inlet-temperatures. Significant advances in turbine cooling effectiveness, as well as thermal barrier coating performance and durability are required to accelerate development of advanced energy systems.

This invention describes a method and apparatus for generating transpiration cooling using a porous ODS high temperature alloy layer in conjunction with near surface embedded microchannel (NSEMC) architectures and film cooling configurations.  The transpiration cooling process reduces superalloy substrate airfoil temperature, resulting in improved turbine component durability.