Performance analysis of supercritical CO2 recompression power cycle with heat transfer characteristics of CO2.

Supercritical CO2 (S-CO2) power cycles have received many attentions recently because a variety of advantages are spotlighted compared with existing power cycle. Supercritical CO2 power cycle can achieve high cycle thermal efficiency and small cycle foot print with high temperature heat sources. Supercritical CO2 has better compatibility with materials of cycle components than steam at high temperature. Also this cycle has high degree of freedom of cycle configuration because cycle is operated on supercritical region of CO2. So many cycle layouts can be configured. Among them, recompression cycle is known as one of the most efficient layouts proper to the applications on sodium-cooled fast reactor or concentrated solar power. To apply in a practical use, characteristics and performance of recompression layout should be analyzed in various conditions. In recompression cycle, two recuperators are important for achieving high cycle efficiency. To consider the relation between recuperators and the performance of recompression cycle, heat transfer characteristics of supercritical CO2 should be involved in cycle analysis. In this study, we conducted performance analysis of recompression cycle with various conditions of recuperators. Also, in given cycle operating conditions, the optimum operation was found and analyzed the results comparatively in a view of physical validity and applicability. The results of this paper can be used to optimize recompression cycle which could be reference values for future analysis.