An examination of regenerative organic Rankine cycles using dry fluids

This paper presents an analysis of regenerative organic Rankine cycles “ORC” using dry organic fluids, to convert waste energy to power from low-grade heat sources. The dry organic working fluids selected for this investigation are R113, R245ca, R123, and isobutane, with boiling points ranging from −12 °C to 48 °C. Regenerative ORC is analyzed and compared with the basic ORC in order to determine the configuration that presents the best thermal efficiency with minimum irreversibility. The evaluation for both configurations will be performed using a combined first and second law analysis by varying certain system operating parameters at various reference temperatures and pressures. Results from these analyses show that regenerative ORC produces higher efficiency compared with the basic ORC while also reducing the amount of waste heat required to produce the same power with a lower irreversibility.