Abstract
Efficiency improvement of thermal power plants is one of the key technologies to protect the global environment. There are many approaches in this regard, which are investigated and developed around the world. Thermal efficiency of fossil power plants has been improved by raising steam temperature as high as 610 Cin a realization of Ultra Super Critical (USC) steam turbine system. In order to enhance the thermal efficiency further, we are developing the Advanced Ultra Super Critical (A-USC) steam turbine system with technical innovations and the reliable design philosophy. A-USC steam turbines will have steam temperature over 700 C, whose thermal efficiency is much higher and carbon dioxide emission is much less than conventional USC plant. There are many aspects and field of technology for the realization of such steam conditions, for instance, material development, cooling design, casing design, and so on. In this paper, we will describe these items well as system design and turbine structure.
