Mitsubishi Heavy Industries Technical Review
    Vol. 52 No. 2 (2015)   Mitsubishi Hitachi Power Systems
    Technical Papers

    Latest Technologies and Future Prospects for a New Steam Turbine

    Eiji Saito,
    Nariyuki Matsuno,
    Keizo Tanaka,
    Shin Nishimoto,
    Ryuichi Yamamoto,
    Shinya Imano

    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.