Performance Assessment and Working Fluid Selection of the Novel Combined Helium Brayton Cycle and Organic Rankine Cycle Based on Solar Power Tower for Sustainable Generation

Numerous irreversibilities exist in the solar subsection of solar power tower (SPT) plants, as was previously recognized, and cannot be prevented. Therefore, it is necessary to develop a new and efficient power generation unit to enhance the performance of the SPT plant. The unique combined cycle for SPT plant was developed in the current study. Working fluid helium was employed in the helium Brayton cycle (HBC), and the medium temperature organic Rankine cycle (ORC) was utilized for waste heat recovery. Using engineering equation solver software, the suggested system's exergy and energy analysis was carried out. Additionally, a parametric study was performed to look into how important characteristics affected plant performance. Simultaneously, working fluid selection study has been performed for ORC. It was concluded that energy efficiency and network output were enhanced by 19.11% and 19.09%, respectively, by implementing ORC to the basic HBC system. The network output, exergy and energy efficiency of the plant (SPT-HBC-ORC) were obtained as 19,135 kW, 39.74% and 37.11%, respectively. The fluid R1233zd(E) was recommended as the thermodynamically best fluid. The current system performs better than supercritical CO2 and the Rankine cycles based systems, according to a comparison with previous studies. Also, present developed solar power system is more efficient and easier to configure compared to previous research to generate the carbon free power.