Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has completed the actual equipment design
of a 1000 MW class tandem compound steam turbine developed in response to recent increasing
demand for the enlargement of the capacity of steam turbines. This paper introduces the latest
steam turbine technologies applied to this state-of-the-art steam turbine including the complete
three-dimensional blade, the low-pressure last stage 50-inch and 60-inch blades, the high
performance exhaust hood, the latest sealing technology, the directed lubrication bearing, the
advanced 12% Cr steel welded rotor, etc. The current steam conditions are equal to 600°C class
USC (Ultra Super Critical), but the practical application of further enhanced steam conditions
through 700°C class A-USC (Advanced Ultra Super Critical) is expected. The Ni-based alloy that
MHPS developed for A-USC plants is expected to attain the targeted value in strength and
underwent a welded rotor for actual-sized rotation tests. Its soundness was verified through a
nondestructive inspection. The practical application of A-USC technology will be in view after the
long term reliability is verified through a rotation test slated for 2016.
