| Project Detail |
Gas turbines produce approximately 35% of the total electricity generation in the U.S. Improving their efficiency is important for reducing energy usage and carbon emissions. Similarly, higher efficiency aviation and other industrial turbines would improve the economics and reduce greenhouse gas emissions in these sectors. Gas turbine efficiency largely depends on the gas temperature at the inlet; the higher the temperature, the higher the efficiency. Gas turbine operational temperature is currently limited by its component materials, particularly those in the path of the hot gas such as turbine blades, vanes, nozzles, and shrouds. Turbine blades experience the greatest operational burden because they must concurrently withstand the highest temperatures and stresses. Currently, turbine blades are made of single crystal nickel (Ni)- or cobalt (Co)-based superalloys. After many years of refinements, their development has plateaued. There is a need to discover, develop, and implement novel materials that work at temperatures significantly higher than that of the Ni or Co superalloys if further efficiency gains are to be realized.
Project Innovation + Advantages:
Current Ni-based alloys used in turbine blade applications operate at 1100°C. This project seeks to develop two classes (Ni) alloys that can continuously operate at 1300°C with coatings, enabling gas turbine inlets of 1800°C or higher. Temperature increases can be achieved through the use of refractory alloys, including molybdenum, niobium, tungsten, and tantalum. Oak Ridge National Laboratory (ORNL) will provide data on alloys and coatings developed by ULTIMATE teams. ORNL will supply technical performance target data, including room temperature and 1300°C mechanical properties, post-exposure mechanical properties for coatings, and physical properties including thermal expansion and thermal conductivity. Additionally, ORNL will provide state-of-the-art characterization of as-received and post-test microstructure of alloys and coatings to assist in interpreting results. Facilities include high temperature furnaces for 1700°C oxidation exposures and frames for mechanical properties testing of creep (deformation) and tensile properties using small- or full-scale specimens. ORNL aims to coordinate with ULTIMATE teams to deliver data within 4 weeks of receipt of specimens for most of the target experiments.
Potential Impact:
Combining development of new ultrahigh temperature materials with compatible coatings and manufacturing technologies has the potential to increase gas turbine efficiency up to 7%, which will significantly reduce wasted energy and carbon emissions. |
