Performance Study on SCO₂ Reheat-Recompression System Based on Advanced Exergy Analysis

Supercritical CO₂ (SCO₂) reheat-recompression system features CO₂ split-flow cooling and dual-stage recuperation design which can reduce power consumption and improve cycle efficiency compared to conventional SCO₂ Brayton cycle. In order to further optimize the SCO₂ reheat-recompression system, a thermodynamic model of the system was set up. Advanced exergy analysis was applied to study system exergy performance, uncovering interactions among components and system optimization potential. Results show that system endogenous exergy destruction constitutes 80.91% of total losses, while avoidable exergy destruction accounts for 33.56%. Component optimization potential priority is ranked as follows: cooler, main compressor, boiler, recompressor, high-temperature recuperator, low-pressure turbine, high-pressure turbine, low-temperature recuperator. Furthermore, enhancing the performance of cooler, low-temperature recuperator, and recompressor can mitigate exogenous exergy destruction of other components. This study provides theoretical guidance for SCO₂ reheat-recompression system optimization.