Design and experimental validation of fuel recirculation solid oxide fuel cell system using Ejector

An ejector-driven fuel recirculation system was designed for 1kW-class solid oxide fuel cell (SOFC), and the power generation experiments were carried out to validate the design procedure and to investigate the fuel recirculation SOFC of the stack performance. An ejector was designed and manufactured taking into account the pressure loss along the anodic loop and the condition of the carbon deposit. The variable mechanism of fuel flow passage in the ejector nozzle enabled to adjust the recirculation ratio of the anode off-gas under constant fuel flow rate. The recirculation ratios were determined from both gas analysis method and the measurement of pressure drop along the anodic loop. The power generation experiments at variable recirculation ratios verify the validity of the design method proposed for the ejector-driven fuel recirculation system in this paper and that the recirculation ratio has not affected the performance of the SOFC stack under the experimental conditions in this paper.