Computational Fluid Dynamics of Supercritical Carbon Dioxide Turbine for Brayton Thermodynamic Cycle

The supercritical gas turbine Brayton cycle has been adopted in the secondary loop of the Generation IV Nuclear Energy Systems, and also planned to be installed in power conversion cycles of the nuclear fusion reactors. Supercritical carbon dioxide (SCO₂) is one of widely considered fluids for this application. The potential beneficiaries include the Secure Transportable Autonomous Reactor - Liquid Metal (STAR-LM), the Korea Advanced Liquid Metal Reactor (KALIMER), and the Battery Omnibus Reactor Integral System (BORIS) which is being developed at the Seoul National University. The reason for these welcomed applications is that the SCO₂ Brayton cycle can possibly achieve higher energy conversion efficiency than the steam turbine Rankine cycle. Gas turbine design is crucial part in achieving this high efficiency. In this paper, a one-dimensional gas turbine analysis methodology is applied for optimal design of the component. Case study result shows that the entire turbine efficiency is increased as hub radius is increased for a same number of stage conditions. Comparing the efficiency which is applied the boundary condition, 4 stage turbines have optimal efficiency.