Comparative performance assessment of solar dish assisted s-CO₂ Brayton cycle using nanofluids

The recent study investigates and compares the energy and exergy performances of solar dish assisted supercritical carbon dioxide re-compression with reheat Brayton cycle. Parabolic dish solar collector with cavity receiver, working on three different thermal oil based nanofluids (Al₂O₃, CuO & TiO₂), is integrated with supercritical carbon dioxide Brayton cycle for power production. A comprehensive thermodynamic analysis and simulations are carried out in engineering equation solver to examine the overall system performance by varying certain operating parameters. These parameters are the solar radiation intensity, wind speed, ambient and inlet temperature of the fluid, mass flow rate in the receiver tube and nano particles percentage. The results demonstrate that Al₂O₃ oil based nanofluid has the highest overall energy and exergy efficiencies, almost 33.73% and 36.27%, respectively, and is almost 0.27% more than TiO₂/oil nanofluid and 0.91% higher than CuO/oil based nanofluid. Effect of the wind velocity on receiver efficiency is also investigated. By increasing the percentage of nano particles, convective heat transfer coefficient of the fluid in the receiver tube also increases. Turbine inlet temperature and pressure ratio is varied to investigate the thermal and exergy efficiencies of the supercritical recompression Brayton cycle.