The design and optimization of a stable 450 W free piston Stirling engine (FPSE) from a geometric and thermodynamic point of view

MSc student: Dominique Biever (SPET/3mE)



Recently Maertens (2011) has developed models to predict stability and engine performance  for a specific medium-scale power Stirling system to convert solar energy into electricity. This engine is a Free Piston Stirling Engine.

The objective of this a new study was to modify and optimize the models to make them applicable for a smaller scale Stirling machine (FPSE) for solar-based operation. These models used design details of the different system components which needed to be designed differently for  small scale application. The updated models were validated by data published in literature for similar engines. The final objective was to propose the geometry for a competitive small scale solar driven FPSE. The peak electrical power of this system should be ca. 450 W with an efficiency of ca. 35 %.

The method used in this study was based on optimization of heat exchangers in the engine. Heat exchangers are key components looking at attainable efficiencies. Void volumes of the heat exchangers were scaled down to find the required volume for best performance.

Since engine stability is limited by mass-spring characteristics of the system, other dimensions had to be analyzed and optimized as well in order to obtain a stable small-scale system

Final colloquium: 30 August 2012