Theoretical analysis of a small-scale solar power system using an R-245fa Rankine cycle with a scroll and twin screw expander

Due to the serious environmental pollution problems caused by the rapid industrialization of modern society, Kyoto Protocol was signed in 1997 to limit the emission of greenhouse gases. Therefore, the concept of renewable energy is being actively studied as an energy source that can replace old fossil fuels, and among these studies the research on solar power has also increased. In this study, the performance of a solar energy applied by R245fa Rankine cycles was analysed by using theoretical method according to the mass flow rate of R245fa. The result shows that the twin screw expander shows 4.8 kW/day under the low solar radiation and 5.8 kw/day under the high radiation conditions. Furthermore, the efficiency of a scroll expander with R-245fa proves to be approximately 8% higher than that with a twin screw expander.