Exhaust diffuser for a turbine

摘要

An exhaust diffuser (2) for a turbine includes an inlet (18) configured to receive exhaust gas from a last stage bucket (14) of the turbine and an exhaust gas guide surface (4) configured to guide the exhaust gas. A curvature of the guide surface (4) comprises a first angle (B) with respect to an axis of the turbine and a ratio of a guide surface axial length (L) to the active length (AL) of the last stage bucket (14) which is between about 0.45 to 0.70. A method of diffusing exhaust of a turbine includes energizing a boundary layer along a curved exhaust flow guide surface (4) of an exhaust diffuser (2) with over tip leakage of a last stage bucket (14) of the turbine. The curved exhaust flow guide surface (4) is at a first angle (B) with respect to an axis of the turbine and a ratio of a guide surface axial length (L) to the active length (AL) of the last stage bucket (14) which is between about 0.45 to 0.70.