During Phase II of the Department of Energy (DOE) funded High Temperature Turbine Technology (HTTT) Program, critical technology development and component verification testing related to the design of an advanced water-cooled gas turbine, firing at 2600°F (1427°C) on low-Btu gas, are being performed by General Electric. A composite construction first stage nozzle was chosen so that low surface temperature [1000°F (538°C)], necessary to control corrosion and high heat flux induced strain, would result. This paper discusses the prototype testing of a three throat segment of this design. The segment consists of two test vanes and a pressure and suction side slave. Hot gas conditions exceeded the design point conditions of 2600°F (1427°C) firing temperature, 166 psia (1.14 MPa) and 6.37 lbm/s (2.89 kg/s) per throat. Nozzle temperatures are presented as a function of firing temperature. Discussion of boiling phenomena which occurred during coolant flow reduction is included. Results are discussed as they relate to verification of the design method and to establishing the “technology readiness” of this design.

An analytic study was conducted to determine the effects of turbine design, airfoil shape and material on particulate erosion of turbine airfoils in coal-fueled, direct-fired gas turbines used for electric power generation. First-stage, mean-line airfoil sections were designed for 80 MW output turbines with 3 and 4 stages. Two-dimensional particle trajectory calculations and erosion rate analyses were performed for a range of particle diameters and densities and for ductile and ceramic airfoil materials. Results indicate that the surface erosion rates can vary by a factor of 5 and that erosion on rotating blades is not well correlated with particle diameter. The results quantify the cause/effect turbine design relationships expected and assist in the selection of turbine design characteristics for use downstream of a coal-fueled combustion process.