These results are similar to those from our previous study on
working fluids for low temperature ORC processes [10] in o2 cycles
with Tmax¼ 100 C and Tmin ¼30 C and internal heat recovery.
There, the thermal efficiencies hthþ show also a modest but
somewhat scattering increase with the critical temperature Tc.
Moreover, the thermal efficiency averaged over all
substances amounts 13.2% which, trivially, is considerably lower
than the values found here for the high-temperature ORC
processes. It is, however, interesting to note that this value is also
just 70% of the Carnot efficiency.