THE RANKINE CYCLE The Organic Rankine Cycle's principle is based on a turbogenerator working as a conventional steam turbine to transform thermal energy into mechanical energy and finally into electric energy through an electrical generator.

The working principle of the organic Rankine cycle is the same as that of the Rankine cycle: the working fluid is pumped to a boiler where it is evaporated, passed through an expansion device (turbine, screw, scroll, or other expander), and then through a condenser heat exchanger where it is finally re-condensed.

The electrical efficiency is around 17% of the total energy input – about 3% higher than traditional steam turbines. The advantages of the ORC system are that it performs well under partial load and, because of the low working pressures and temperatures, it is not subject to the regulations of steam equipment.

ORC is the Rankine process, where instead of the water some organic compound is used as a flowing medium (toluene, isobutene, isopentane or silicon fluids). ORC is one way to generate electricity and heat in lower temperatures. Heat from evaporation of organic fluid is less than that of water.