Multi-scale simulation of solid oxide fuel cell power units

A multi-scale physically-based model is presented in this study in order to quantitatively assess the effect of geometrical modifications and working conditions in an existing SOFC small power unit. The model, validated in different operating conditions, describes transport and reaction phenomena within the electrodes and the feeding channels through conservation equations, while the electrode microstructural properties are evaluated through the particle-based three-dimensional reconstruction of the microstructure. The model is able to capture the main chemical and physical phenomena occurring from the microscale to the macroscale, thus predicting the power output from the knowledge of the same input parameters available in reality, such as powder characteristics and operating conditions. The presented simulations rationalize how the power unit behaves upon a variation in flow configuration, operating temperature and cell geometry, thus providing a tool to predict how to optimize and control the operation of an SOFC system.