Effects of size and volume fraction of alumina nanoparticles on the performance of a solar organic Rankine cycle

•A solar organic Rankine Cycle was considered using dish collector as the heat source.•The performance of three cavity receivers was modeled and compared.•A hemispherical cavity receiver was experimentally investigated.•Alumina/thermal oil was investigated as the solar working fluid.•The system was evaluated at different sizes and concentrations of nanoparticles. The objective of this work is the investigation of a solar-driven organic Rankine cycle with nanofluid-based solar dish concentrator. Three different cavity receivers are tested with the alumina/oil nanofluid in order to determine the most effective choice. More specifically, the examined cavities are hemispherical, cubical, and cylindrical, while the organic Rankine cycle is a non-regenerated system with superheating, R601 working fluid and heat rejection temperature at 310 K. The analysis is perfumed using the first and the second thermodynamic laws. The organic Rankine cycle is investigated for different pressure in the turbine inlet and different nanoparticle concentrations are also studied. According to the results, the thermal performance of the cavity and the electricity production are improved by decreasing alumina nanoparticle size, and by increasing the nanofluid concentration. Moreover, the optimum pressure in the turbine inlet was found at 2 MPa. Finally, the hemispherical cavity receiver has been found to be the best choice with cubical to be the second one and the cylindrical to be the less effective choice.