Supercritical CO2 hybrid Brayton–Organic Rankine Cycle integrated with a solar central tower particle receiver: Performance, exergy analysis, and choice of the organic refrigerant

A study of the integration of a supercritical CO${}_2$ hybrid Brayton–Organic Rankine Cycle (ORC) with a Concentrated Solar Power (CSP) system using a particle receiver is presented. It focuses on evaluating the energy and exergy performance of the system to improve its efficiency and reduce fuel consumption. The particle receiver uses a mixture of silicon carbide and air as the working fluid, allowing operation at higher temperatures suitable for coupling with the supercritical CO${}_2$ Brayton cycle. Detailed thermodynamic models were developed using Mathematica and Engineering Equation Solver (EES) to simulate the behavior of the system under various conditions. The results show that coupling the particle receiver with the hybrid Brayton cycle significantly reduces fuel consumption by 63.2%. The exergy analysis shows that the highest exergy destruction occurs in the heat exchangers of the entire system, indicating potential areas for further efficiency improvements. The study also highlights the critical role in system performance of the ORC working fluid used in the bottoming cycle. Among the fluids tested, R600a was found to be the most effective, providing the highest efficiency under the considered conditions. The results highlight the potential of integrating particle receivers into CSP systems to improve both the energy efficiency and sustainability of power generation, and thus, it represents a promising approach for achieving more effective and sustainable power generation.