The use of various working fluids have been studied in the
literature and correlations have been proposed for the prediction of
process efficiencies. Liu et al. [2] proposed an equation for the
prediction of the thermal efficiency of an ORC plant using isentropic
fluids, based on the evaporation, condensing and critical temperatures
of the working fluid. The equation was shown to be in
reasonable agreement with a limited number of model results. Teng
et al. [3] derived a very similar relation in 2007 [3]. Recently,Wang
et al. [4] also described a similar correlation. Kuo et al. [5] presented
a thorough study of the Jacob number which was shown to be very
useful for the prediction of thermal efficiency. Additionally, a new
figure of merit was able to extend the use of the Jacob number, to
make predictions at various condensation and evaporation temperatures.
Wang et al. [6] later included the Jacob number in two
prediction models: one for thermal efficiency and one for exergetic
efficiency.