Solid oxide fuel cell modelling: electrochemical performance and thermal management during load-following operation

For solid oxide fuel cell (SOFC) energy systems, the development of an appropriate thermal management is a fundamental issue. Specifically SOFC, during load following operation, could face thermal stresses that can lead to performance degradation and to a consequently strong reduction of their lifetime. In this research work, SOFC dynamic model, based on electrochemical reaction and enthalpy balance equations, was developed. The modelling activity and the consequent model validation were carried out basing on experimental data obtained from a test campaign on a short stack. The implemented tool permits, in load following operation, to regulate SOFC temperature at a fixed value, adjusting instantaneously the cathodic air flow rate varying the air utilization factor (Uox). At the same time, the model allows the evaluation of the transient behaviour of the main system parameters as: equivalent hydrogen flow rate, current and operating voltage.