This seminar will summarize the outcomes of the different research projects dealing with kW-scale ORC (Organic Rankine Cycle) power systems that have been conducted for more than 10 years at the University of Liège.
The experience gained with the different experimental studies will be discussed. These studies covered the characterization of prototypes of volumetric expanders (scroll, screw, piston, roots), turbines (radial inflow, axial), heat exchangers and pumps, as well as the comparison of performance achieved with several working fluids (including organic fluids and water). Specific experimental techniques and their use in the process of model calibration will be presented. Among these techniques, the measurement of the charge division among components will be highlighted.
The development, in different simulation platforms, and the experimental validation of steady-state and dynamic simulation models will be presented. The use of these models for the design optimization of components and systems, for the investigation of advanced control strategies and for the comparison of innovative architectures, will be highlighted. Advanced control strategies (including Model Predictive control and advanced PID) are particularity suitable to ORC coupled to highly transient heat sources. Innovative architectures include trilateral and super-critical cycles better adapted to some heat sources. Finally, special applications of ORCs, such as waste heat recovery from internal combustion engines, CHP and pumped thermal energy storage, will be presented. For all these applications, opportunities and challenges will be listed and discussed.