A New High Efficiency Gas Turbine for Mechanical Drives

This paper discusses the design and development program that is taking place to enable the availability in mid 1999 of a unit designated the Coberra 6761. This features the aircraft derivative Rolls-Royce RB211-24G upgrade gas generator and a new close coupled Cooper-Bessemer RT61 three stage power turbine. The paper describes the upgrade of the gas turbine from 28.4MW (38 000 SHP) to 31.8MW (42 600 SHP) ISO output power at over 40% thermal efficiency. Measures taken to maximize reliability and maintainability while reducing cost of ownership are described. The improvements in the gas generator compressors and turbines are detailed. The new design features of the power turbine are reviewed including a new support structure, modular service features and 3D orthogonal airfoil designs. The forthcoming validation program for the entire gas turbine unit is also discussed.