The selection of working fluids has been treated in a large
number of scientific publications. In most cases, these studies
present a comparison between a set of candidate working fluids
in terms of thermodynamic performance and based on a thermodynamic model of the cycle.
When selecting the most appropriate working fluid, the
following guidelines and indicators should be taken into account:
(1) Thermodynamic performance: the efficiency and/or output
power should be as high as possible for given heat source
and heat sink temperatures. This performance depends on a
number of interdependent thermodynamic properties of the
working fluid: critical point, acentric factor, specific heat,
density, etc. It is not straightforward to establish an optimum