Development of New Advaneced Low Pressure End Blades for High Efficiency Steam Turbine(Special Issue on International Conference on Power and Energy System)

A low pressure end blade is one of the most important elements in designing the steam turbine, because it determines the performance, the dimension, and the number of casings of the turbine. Applying the state of the art technology to the aerodynamic and mechanical design, Mitsubishi Heavy Industries, Ltd. has been conducting a development program of new advanced low pressure end blades which adopt the ISB (Integral Shroud Blade) structure. A new standard series of these low pressure end blades has already been completed for 50 Hz and 60 Hz unit application including 3600 rpm 45 inch titanium blade, 3000 rpm 48 inch steel blade, and 1500/1800 rpm 54 inch steel blade which have the largest exhaust annulus area among the same class blades in the world. This paper reports on the up-to-date design technology applied to the new advanced low pressure end blades and on the verification tests to ensure the high efficiency and the reliability of the developed blades.