The present work aims at investigating the energetic
performances of Organic Rankine Cycles (ORCs) for the
exploitation of low temperature heat sources in small-scale
applications. Specifically, a thermodynamic model has been
developed and a parametric energy analysis has been carried
out considering several organic fluids.
Different system configurations have been investigated in
order to define the proper ORC arrangements and the influence
of the operating conditions on the system performances.
Subcritical and transcritical cycles, with saturated and
superheated conditions at the expander inlet, have been
analysed and the impact of internal regeneration on ORC
behaviour has been studied.
The analysis shows the large influence of the operating
conditions and the significant effect of the internal regeneration
on the system performances. Specifically, the comparison
between the different ORCs highlights that the transcritical
cycle with internal heat exchange offers the maximum electric
efficiency. Furthermore, results reveal that the proper selection
of the organic working fluid is fundamental to maximise the
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.