The evaluation of CFCC liners after field testing in a gas turbine - V

Under the Ceramic Stationary Gas Turbine (CSGT) and Advanced Material Program sponsored by the U.S. Department of Energy (DOE), a team led by Solar Turbines Incorporated (Solar) has successfully designed engines utilizing SiC/SiC continuous fiber-reinforced ceramic composite (CFCC) combustor liners. Their potential for low NO_x and CO emissions was demonstrated in ten separate field-engine tests for an accumulated duration of more than 68,000-hours. In the first four field tests, the durability of the CFCC liners was limited primarily by the long-term stability of SiC in the high-pressure steam environment of the gas turbine combustor. Consequently, the need for an environmental barrier coating (EBC) to meet the 30,000-hour life goal was recognized. An EBC developed under the National Aeronautics and Space Administration (NASA) High Speed Civil Transport, Enabling Propulsion Materials (EPM) program was improved, optimized and applied on the SiC/SiC liners by United Technologies Research Center (UTRC) from the fifth field test onwards. Presented in this paper is the evaluation of the field test with a modified EBC using Strontium Aluminum Silicate (SAS) on SiC/SiC CFCC liners after 8,368-hours.