Ahead of Print Archive Most Accessed Articles F.A.Q. Copyright Form Author Contribution Form WOS-Journal.info In titlesIn abstractsIn keywordsIn authors ... Exergy, energy, exergoenvironmental assessment of a novel combined helium Brayton cycle and transcritical CO2 cycle for solar power tower applications

This study introduces a combined cycle that captures solar energy from a solar power tower for power generation.The system couples a helium-based Brayton cycle (topping cycle) with a transcritical carbon dioxide cycle (bottoming cycle), where the latter recovers and uses the waste heat released from the Brayton process.A detailed investigation was carried out, incorporating energy, exergy, and exergoenvironmental evaluations, to assess the overall performance of the combined power plant.The findings demonstrated a significant improvement of 12.05% in the energy efficiency of the helium-based Brayton cycle when the transcritical carbon dioxide cycle was incorporated as a bottoming configuration.The plant's optimal operating parameters were identified, giving peak values of 23.2% for energy efficiency, 24.83% for exergy efficiency, and 14,930 kW for power output.A detailed examination of the solar subsystem components (receiver and heliostats) revealed the maximum exergy destruction occurs in these parts of the solar plant, totalling around 37,578 kW.The total exergy destruction across the plant was calculated to be 45,164 kW.The exergoenvironmental impact coefficient exhibited a substantial value of 4.028, primarily attributed to the lower exergy efficiency of the plant.Additionally, the energetic stability factor was found to be 0.2483.This research contributes to solar power tower integration, enhancing efficiency, and achieving a simplified system with fewer components compared to previous studies.