Organic Rankine Cycles (ORC) are systems that can effectively recover low-grade heat for electric power generation. For ORC to be a viable technology, it should operate safely and efficiently under variable operating conditions due to exogenous and operating specifications changes.

This process was developed in 1859 by Scottish engineer William J.M. Rankine. This is a thermodynamic cycle which converts heat into mechanical energy—which usually gets transformed into electricity by electrical generation.

Real Rankine cycle (non-ideal) In a real power-plant cycle (the name "Rankine" cycle is used only for the ideal cycle), the compression by the pump and the expansion in the turbine are not isentropic. In other words, these processes are non-reversible, and entropy is increased during the two processes.

A simple Rankine cycle is based on pressurizing water with a pump, heating the pressurized water beyond its boiling point to produce superheated steam in the boiler, expanding the steam through a steam turbine, cooling the residual steam to regenerate water, and returning the water to the pump to start through the ...