SOLAR HETEROGENEOUS ORGANIC RANKINE CYCLE

Abstract

Summary: The present thesis work studies the opportunities of performance improvement related to Solar Organic Rankine Cycle using heterogeneous organic working fluids, which are predicted to increase the thermal efficiency of the cycle from a thermodynamic point of view. This cycle is of critical importance since it can be integrated in multiple industrial plants helping in the waste heat recovery, which is a cost effective and environmentally friendly solution. In the study, an investigation was carried out on three stages. The first stage was the selection of pure working fluids, which are suitable for cost efficient low temperature scale solar application. The second stage was a comparison between heterogeneous organic working fluid mixtures and pure working alternatives. Third, all the heterogeneous working mixture alternatives that did not achieve an increase in either thermal efficiency or savings were eliminated. Finally, the optimum alternatives of heterogeneous mixtures were indicated after multiple screening steps as water normal hexane and water cyclohexane mixtures, which showed promising results in terms of thermal efficiency increase taking into consideration cost savings and safety limitations.