The ORC-concept has two circuits, one for thermal oil and another for organic fluid. Heat from burning fuel or industrial waste is led in via the oil-filled circuit at a temperature of 250–300 °C to the heat exchanger, creating steam and super heating the organic silicon fluid.

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.

Steam Rankine cycle is known as one of the main power-generating cycles, which consists of four key devices, namely a boiler (heat exchanger), a steam turbine, a condenser (heat exchanger), and a pump, as illustrated in Fig. 28.

The organic Rankine cycle is is similar to the Rankine steam cycle, but uses an organic fluid such as refrigerants and hydrocarbons instead of water as the working fluid. The ordinary Rankine cycle uses thermal power to convert water to steam, which expands through a turbine in order to generate electricity.