The incentives for a water-cooled gas turbine have been previously presented by Caruvana et al. 1 The ongoing water cooling development effort at General Electric, including the successful operation of a 9.7 in. (24.7 cm) dia laboratory turbine at firing temperatures up to 3500 F (1927 C), has been described by Horner et al. 2 An important portion of this effort is wheelbox testing wherein water transfer, distribution, cooling, collection, and erosion are being studied in full-scale rotating hardware of the General Electric MS-7000 size gas turbine. In addition, rotor dynamic and bucket tip water discharge characteristics are being obtained for the design of a full size water-cooled gas turbine. Discussed are the design of the rather unique test vehicle and the results obtained from the initial test phase. Results from the second phase of testing, to be conducted in late 1978, will be the subject of a future paper. This effort has been funded under the EPRI Water-Cooled Gas Turbine Development Project.

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.