抄録
This paper describes the conceptual design of 1700℃ class high temperature turbine in closed-cycle gas turbine system. In this system, the power generation efficiency is aimed to be 60%(HHV) or higher. The turbine was planed high efficiency by turbine gas flow path optimal design, the cooling design that makes cooling and seal flow the minimum. The cooling design of first stage blades, which were served in hot steam flow, was carried out. The hybrid cooling method combining closed circuit passage with a partially open circuit one was chosen among several cooling systems from a point of plant efficiency and durability of cooling blades. The several elemental tests such as outer heat transfer coefficient on airfoil, internal heat transfer one in cooling channel and pressure loss coefficient in rotor cooling passage. As a result of the present conceptual design, then cooling steam consumption in the first stage is reduced by about 40% compared with that of WE-NET phase I design.
