Flexible and controllable ORC turbine for smart energy systems

A concept for a flexible and controllable Organic Rankine Cycle (ORC) turbine is presented. The ORC is a thermodynamic process for the conversion of heat into mechanical work, resp. electricity. The process is used e.g. for converting exhaust heat from block heat and power plants or heat from solar power plants into electricity. ORC turbines are particularly attractive for regional renewable energy systems with fluctuating demand and production of both electricity and heat.. However, today's ORC systems lack flexibility because they are only efficient at the operating point for which they were optimized. This contribution presents a two-staged ORC turbine with a set of efficient operating points. Furthermore, a sophisticated control system based on the operator controller module (OCM) approach is developed. With the physical system having sufficient thermodynamic flexibility and the control system having the capability to use it, the overall system is capable of being controlled by a self-optimizing planning system connected to smart power grids and smart heating grids. The required degrees of freedom (DoF) of the physical system and the actuator/sensor/controller structure based on the OCM model allow for the application of a “smartification process”.