Leslie John Faulder

Ceramic Stationary Gas Turbine Development Program: Third Annual Summary

The Ceramic Stationary Gas Turbine (CSGT) program has been performed under the sponsorship of the United States Department of Energy, Office of Industrial Technologies and Office of Power Technologies. The objective of the program was to improve the performance of stationary gas turbines in cogeneration by retrofitting uncooled ceramic components into the hot section of the engine. The replacement of previously cooled metallic hot section components with the uncooled ceramics enables improved thermal efficiency, increased output power, and reduced gas turbine emissions. This review summarizes the latest progress on Phase III of the program, which involves 1) preparation for the final in-house CSGT engine test of ceramic blades, nozzles and CFCC liners, and 2) field testing of the CFCC combustor liners at two cogeneration end user sites. The field testing of CFCC combustor liners is now being performed under the Advanced Materials Program, sponsored by DOE, Office of Power Technologies.The Solar Centaur 50S engine, which operates at a turbine rotor inlet temperature (TRIT) of 1010°C, was selected for the developmental program. The program goals include an increase in the TRIT to 1121°C, accompanied by increases in thermal efficiency and output power. This is to be accomplished by the incorporation of ceramic first stage blades and nozzles, and a “hot wall” ceramic combustor liner. The performance improvements are attributable to the increase in TRIT and the reduction in cooling air requirements for the ceramic parts. The “hot wall” ceramic liners also enable a reduction in gas turbine emissions of NOx and CO. This 1121°C TRIT engine test of the ceramic hot section is planned for the first quarter of 2001.The component design and material selection have been previously definitized for the ceramic blades, nozzles and combustor liners. Each of these ceramic component designs was successfully evaluated in short-term engine tests in the Centaur 50S engine test cell facility at Solar. Environmental barrier coatings for the ceramic components are also being optimized. To date, seven field installations of the CSGT Centaur 50S engine totaling over 30,000 hours of operation have been initiated under the program at two industrial cogeneration sites. This paper briefly discusses the recent developmental efforts for the upcoming 1121°C TRIT engine test, but focuses on the various field demonstrations of CFCC combustor liners.Copyright

Ceramic Stationary Gas Turbine Development Program — Design and Test of a First Stage Ceramic Nozzle

The goal of the Ceramic Stationary Gas Turbine(CSGT) Development Program, under the sponsorship of the United States Department of Energy (DOE), Office of Industrial Technologies (OIT), is to improve the performance (fuel efficiency, output power, exhaust emissions) of stationary gas turbines in cogeneration through the selective replacement of hot section components with ceramic parts. Phase II of this program includes detailed engine and component design, procurement and testing. This paper will review the design and test of the first stage ceramic nozzle for the Centaur 50S engine. For this test an uncooled monolithic ceramic nozzle made from SN-88 silicon nitride(NGK Insulators Ltd.) was used.A major challenge in the successful introduction of ceramic parts into a gas turbine is the design of the interface between the ceramic parts and metallic components. The design and attachment of the ceramic nozzle was greatly influenced by these considerations. Metallic components in the stationary structure of the turbine have been added or redesigned to retrofit the ceramic nozzle into the all metallic Centaur 50S engine.This paper will also discuss special handling and assembly techniques used to install the ceramic nozzle into the engine. Trial assemblies were used in the engine build process, this proved most beneficial in identifying problems and reducing the risk of damage to the ceramic nozzles. Assembly techniques were designed to reduce assembly loads and to eliminate blind assemblies.Before installing any ceramic nozzles into the engine they were first required to successfully pass both mechanical and thermal proof tests. Details of these proof tests and the final full load engine test will be described in this paper. The engine test was run at a turbine rotor inlet temperature(TRIT) of 1010°C. Total number of engine starts was six, and the total run time was approximately 10 hours.Copyright