Selection of working fluids for organic rankine cycle (ORC) in waste heat power generation system

Abstract

Selection of working fluid is crucial in designing an ORC system. A selection process to get potential pure working fluids for medium-temperature ORC processes has been investigated. Stability, safety and environmental aspects were considered firstly. Then vapor specific volume, latent heat, normal boiling point and critical point of refrigerants and non-refrigerating fluids are analyzed and net power output and cycle efficiency of the ORC system were calculated. Finally, 17 pure fluids were selected for the heat sources of 420 K, 470 K and 520 K respectively. The results indicated that refrigerants such as R245fa, R245ca and R365mfc are good enough for recovering waste heat of temperature ranged from 350 K to 520 K and the optimal turbine inlet pressure was ranged from 1.0 to 1.5 MPa.