Real Rankine Cycle PV Diagram A real Rankine cycle or non-ideal cycle used in actual power plants do not undergo isentropic compression and expansion by pump and turbine respectively. These processes are irreversible compared to the ideal cycle, and there is an increase in entropy as shown in the T-s diagram below.

The Rankine cycle is named after William John Macquorn Rankine, a Scottish polymath professor at Glasgow University. Heat energy is supplied to the system via a boiler where the working fluid (typically water) is converted to a high-pressure gaseous state (steam) in order to turn a turbine.

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 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.