Thermodynamic Efficiency of Irreversible Cyclic Processes in Cooling Devices

To estimate the ultimate efficiency of cryogenerators with various design schemes, some idealized cyclic irreversible processes are considered which allow the cooled gas temperature to be increased and the heat to be rejected for the restoration of the initial temperature level. Simple analytical expressions are derived for various working parameters of the processes. In case of the ideal gas, when there is no Jole-Thompson effect, the ultimate efficiency is estimated as 0,5.