An additional important criterion is the maximum cycle pressure. The latter should be chosen
while accounting for the maximum temperature of engine exhaust gases and the temperature of
jacket cooling water and scavenged air after the compressor (C) of turbocharger (T/C). In this paper,
a supercritical cycle under 45 bar maximum pressure has been selected. Currently, steam turbine
expanders ranging from a few kW up to 3 MW are used in ORC processes achieving high internal
turbine efficiencies. Steam turbines over 0.5 MW in ORC achieve internal efficiencies near 85% [34,35],
and isentropic turbine efficiency up to 90% is achievable in individual designs. Colonna et al. [36]
stated that typical the isentropic efficiency design value is 87%. The efficiency is higher than that of a
steam turbine because the maximum pressure and mass flow rate are much higher, while the expansion
is completed within the superheated region.