Similar to a simple Rankine cycle, a basic organic Rankine cycle (ORC) consists of four processes: increasing pressure of the working fluid through a pump, high temperature heat addition through an evaporator, expansion of the high temperature as well as high pressure fluid through a turbine, and low temperature heat ...

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 Rankine cycle or Rankine Vapor Cycle is the process widely used by power plants such as coal-fired power plants or nuclear reactors. In this mechanism, a fuel is used to produce heat within a boiler, converting water into steam which then expands through a turbine producing useful work.

A basic ORC consists of four main components: an evaporator, an expander, a condenser, and a pump. Figure 1 shows the simplest ORC configuration. As can be seen, liquid in saturated conditions (1) is pumped, increasing its pressure, into the evaporator (2) where it is evaporated by supplying energy in the form of heat.