Helium gas turbine of high temperature gas cooled reactor

Takada, Shoji; Takizuka, Takakazu; Yan, X.; Kunitomi, Kazuhiko 

Gas Turbine High Temperature Gas Reactor GTHTR300 is a direct cycle system in which reactor outlet helium gas at 850C is used to drive gas turbine. The design direction was to improve economics by combining existing technologies without breakthrough far from current technology level. The power conversion system design employed non-inter cooled regenerative cycle. The 3-dimensional blade design of the turbine and compressor, in which inlet blade angle was matched with inlet angle of flow, achieved high polytropic efficiencies of 93% and 90%, although they have disadvantages of high boss ratio and stage numbers. As the results of the design, the electric cost was estimated to be below 4 yen/kWh showing the economic competitiveness against LWRs. To establish design method of high efficiency helium gas compressor, a 1/3 scale compressor model aerodynamic performance test was carried out to design the inlet blade angle around the endwall to reduce endwall boundary layer thickness, as well as to modify coefficients of correlations for design. The design of high efficiency helium gas compressor was completed to fulfill the target efficiency of 90.5%.