Thermodynamic analysis of a simple Organic Rankine Cycle

New expressions for thermal efficiency of a subcritical and supercritical simple ORC are proposed. For a subcritical ORC without the superheat, thermal efficiency is expressed as a function of the Figure of Merit (FOM), while for the superheated subcritical ORC thermal efficiency is given in terms of the modified Jacob number. For the supercritical ORC, thermal efficiency is expressed as a function of dimensionless temperature.