van Heule, XanderSkiadopoulos, TasosManolakos, DimitrisDe Paepe, MichelLecompte, Steven2026-03-042024-07-2520242024-05-102024978844722745710.12795/9788447227457_28https://pepa.une.es/handle/123456789/70132The Trilateral Flash Cycle (TFC) is an alternative to the Organic Rankine Cycle (ORC). The TFC have been shown to have greater exergy efficiencies compared to the ORC in low-grade heat-to-power conversion. This is a result of the more efficient heat transfer from the heat carrier to the working fluid, even though the TFC has inherently a lower thermal efficiency. However, these results are based on cycle modeling assuming equilibrium conditions, but the actual two-phase expansion process is a nonequilibrium process. Thermal non-equilibrium between vapour and liquid occurs during the evaporation (or flashing) of the working fluid during the two-phase expansion process. The liquid phase has a temperature greater than the corresponding pressure’s saturation temperature and the equilibrium assumption overestimates the actual vapour quality. In a previous work, this non-equilibrium expansion was modeled and predicted based on the homogeneous relaxation model (HRM). In this work, the impact of the non-equilibrium process on the efficiency of the TFC is investigated and compared to the equilibrium model. The overall power recuperation is around 86% lower when including the thermal non-equilibrium nature of the expansion process. Therefore, the thermodynamic non-equilibrium losses should thus be incorporated when predicting the performance of a TFC.Libro digitalpp. 176-183Creative Commons Attribution 4.0 International (CC BY 4.0)Creative Commons Attribution 4.0 International (CC BY 4.0)http://creativecommons.org/licenses/by/4.0/openAccess