中低温热能驱动的非共沸工质有机Rankine循环

The organic Rankine cycle (ORC) is a mainstream technology for efficient heat-power conversion of low-to-medium temperature thermal energy below 200℃. Zeotropic mixtures effectively reduce the heat transfer exergy losses, complement the advantages of pure components, and extend the working fluid useful temperature range. Thus, zeotropic mixtures are being rapidly accepted into the ORC field. This paper summarizes the research progress by the authors' team in optimizing the design of ORC systems using zeotropic mixtures. Conventional ORC systems using zeotropic mixtures have been expanded by the introduction of dual-pressure evaporation cycles to improve the temperature matching during evaporation and significantly reduce the heat transfer losses. The liquid-separation condensation method is also used to increase the condensation heat transfer rate of the zeotropic mixtures which greatly reduces the system cost. In summary, zeotropic mixtures can significantly improve the thermodynamics of ORC systems while the liquid-separation condensation method can effectively reduce the large heat transfer areas and improve the poor thermo-economic performance of systems using zeotropic mixtures. Thus, zeotropic mixtures then have favorable prospects for use in ORC systems.