Development of Ultra Super Critical Plant

Abstract

Outline of USC research and development
Since our country mostly depends on the import of the primary energy such as oil and coal from foreign countries, the energy supply structure is fragile. Therefore, it is a latently essential problem to suppress and diversity the consumption of energy and reduce its cost. Also, it is important to enhance efficiency of a thermal power station in order to cut down on CO₂ from the viewpoint of global environmental problem.
Under these circumstances, an ultra high pressure and high temperature of a steam condition, that is. Ultra Super Critical Steam Condition (USC) pressure power generation has been under development as work subsidized by the Agency of Natural Resources and Energy in the Ministry of International Trade and Industry since 1982. Research and development has been achieved so far on a ferritic material at a steam temperature of 593°C and austenitic material at 649°C, which showed that this power generation can be technically put to practical use.
However, as far as austenitic material is concerned, it is difficult to operate the actual machine at the present fuel cost because of operational restrictions due to material characteristice (a coefficient of thermal expansion is great and a coefficient of heat transfer is small), material cost, etc.. For this reason, the heat resisting limit of ferritic material has been considered to be 600°C up to the present. It is decided to set the target limit to 630°C and continue the reseach and development.