Thermo-Economic Analysis of Waste Heat Recovery ORC Using Zeotropic Mixtures

Abstract

Organic Rankine cycle (ORC) has been examined as an effective way to recovery waste heat from industrial manufacture. The effects of internal heat exchanger (IHE) and superheat degree on the thermoeconomic performance of ORC are presented in this paper. Zeotropic mixtures are employed in the simulation and six indicators are used to evaluate the system performance, as follows: (1) net power output, (2) thermal efficiency, (3) exergy efficiency, (4) cost per net power output (CPNPO), (5) area of the heat changers per net power output (APNPO), and (6) energy saving and emission reduction performance (ESERP). The results indicate that the more volatile pure component has a higher increasing rate of net power output when IHE is equipped. The IHE has a greater impact on thermal efficiency and exergy efficiency of the ORC with zeotropic mixtures than that of the ORC with pure fluid. For the ORC with both mixtures and pure component, the rising superheat degree results to the decline of the net power output but increase of the thermal efficiency, and exergy efficiency at the constant turbine inlet pressure. Both the basic ORC and regenerative ORC with zeotropic mixtures have a better economic performance than that with pure fluid. In addition, superheat degree has a negative effect on the economic performance of ORC with more volatile component mixtures.