SBIR-STTR Award

Since around 1970 the commercialization of ceramic gas (Brayton-cycle) turbines has been a goal of the Department of Energy and its predecessors in the US (e.g., the Advanced Gas Turbine program and several others), as well as in other countries, because ceramic turbines hold the promise of operation at gas (turbine inlet) temperatures of 1375 C (2500 F) and above, at which cycle thermal efficiencies can be very high (e.g., over 50%). All efforts were unsuccessful. The combination of alternative turbine system designs, improvements in ceramics, and now just recently, significant advances by Saint-Gobain in low-cost volume manufacturing of large-diameter silicon nitride blisks (blades plus disks) offer a meaningful opportunity for success. A totally new turbine system design approach is proposed, involving peripheral speeds under half (below 300 m/s) those used in many earlier turbines, generally in axial-flow rather than radial-inflow configurations, thus greatly reducing steadystate stresses, and thereby enabling the use of ceramics. Saint-Gobain

The commercialization of ceramic gas (Brayton-cycle) turbines in the range of 50 kWe to 1.5 MWe has been a tantalizing challenge for many organizations for nearly forty years, because ceramic turbines hold the promise of operation at turbine inlet temperatures of 1400 deg C (2550 deg F) and above, at which point cycle thermal efficiencies can be very high, potentially over 50%. All efforts to date have been unsuccessful. Now, the combination of new turbine system designs, ceramics improvements, and advances in lower-cost manufacturing of largediameter silicon nitride blisks (blades plus disks) offer a meaningful opportunity for success. A totally new turbine system design approach is proposed, involving axial-flow configurations with peripheral speeds under half (below 300 m/s) of those used in many earlier turbines, thus greatly reducing steady-state stresses, and thereby enabling the use of ceramics. New potential to manufacture low-cost blisks of silicon nitride holds promise for low-cost, high-efficiency engines up to 1.5MWe and is the key breakthrough that ceramic gas turbines have needed in order to offer promise of success. The Phase 1 design and analysis feasibility studies primarily focused on Wilson TurboPower