Analysis of supercritical CO2 brayton cycle system for laser inertial confinement fusion concept reactors

Abstract

The large temperature difference between the PbLi and S-CO 2 cooling loops in a laser inertial confinement fusion reactor complicates efficient heat recovery and can degrade the performance of a conventional single-source power-conversion system. To address this issue, this study proposes a dual-heat-source recompression S-CO 2 Brayton cycle for a 200 MW laser inertial confinement fusion concept reactor. A lumped-parameter thermodynamic model was established to optimise the cycle configuration under given conditions. Subsequently, the resulting design parameters were applied to the VITARS model for steady-state validation and transient analysis. The optimized cycle achieved a thermal efficiency of 44.2%, with an S-CO 2 mass flow rate of 782.90 kg/s and a pressure range of 9.236-25.00 MPa. During a reduction in reactor power from 100% to 80%, the turbine output decreased smoothly to approximately 90 MW and the system reached a new steady state after about 8,000 s. A 5 K increase in cooling-water temperature increased the final mass flow rate by 2.02%. These results demonstrate that the proposed cycle can effectively couple the dual-temperature blanket heat sources, provide competitive thermo-economic performance, and maintain stable behavior under representative transient disturbances.