News from Japan

Demand for global cooperation to help reduce carbon dioxide emissions and suppress the greenhouse effect has been growing. Longer service lifetimes for machinery, and therefore reduced maintenance and replacement costs, are also being required by users. As a result manufacturing companies have been working hard to develop higher efficiency devices and machines. The stator coils of large-capacity turbine electric power generators need to be cooled. For this purpose, water (with much higher cooling efficiency than air) is commonly circulated through pipes in side the coils. However, this procedure re quires a water circulator and inlet and out let piping. If stator-coil conductors could be cooled indirectly by hydrogen gas in contact with the conductor insulation layers, the cooling system could be greatly simplified and higher efficiency achieved. This article describes the world´s largest capacity hydrogen-cooled turbine generator, developed and supplied by Toshiba.