Recuperators investigation for high temperature supercritical carbon dioxide power generation cycles

Highlights: • Steady-state modeling of s-CO₂ recompression cycle comparing two different tools. • Segmental design method and analysis of PCHE recuperators. • Heat transfer and fluid flow characteristics effect on recuperators effectiveness. • Investigation of operating conditions resulting in an efficiency greater than 46%. - Abstract: Supercritical carbon dioxide (s-CO₂) Brayton cycles are a promising technology for the next generation power conversion cycles, attaining equivalent or higher cycle efficiency compared to conventional power cycles at similar temperatures (550–750 °C). The recompression cycle attracts the main research interest among the s-CO₂ layouts. Recompressing a fraction of the flow without heat rejection, results to an increase in thermal efficiency, while the majority of heat transfer occurs in recuperators. In this study, a thermodynamic analysis of a 600 MW_th power cycle has been carried out using two different simulation tools to model the recompression system. The analysis focuses on the parameters that have the most significant impact on the components and cycle efficiency. A segmental analysis of the recuperators took place to assess the effect of flow characteristics on the heat transfer. Finally, a comparative analysis of the results of the two simulation tools versus the results of a reference cycle from literature is carried out, showing that the prediction of the overall heat transfer coefficient and recuperator effectiveness between the developed code and reference model has a maximum deviation of 4%, whereas the prediction deviation between the commercial software and reference model is about 2.8%.