Thermal Analysis of Organic Rankine Cycle Using Different Organic Fluids

A thermodynamic analysis of the Organic Rankine Cycle (ORC) is presented based on the first law of thermodynamics to find out the effect of the organic fluid selection on the cycle efficiency and power output. Different configurations of ORCs with and without Internal Heat Exchanger (IHE) are used. The criteria used to choose the optimum working fluid are discussed and many different organic fluids are compared in terms of the thermal efficiency and power output. The results obtained show that higher efficiencies are obtained for ORC with IHE configuration, and that the organic fluid R123 has the most favorable performance, for which the thermal efficiency of ORC is 14.2 and 13.28 with and without IHE, respectively. Moreover, the work output of ORC is about 50 kJ/kg, which is the highest when R123 is used as an organic fluid.