Analysis of Transient Response of Solid Oxide Fuel Cells with Anode Off-gas Recycle

In this work, a solid oxide fuel cell system with anode off-gas recycle (AGR-SOFC) model which is composed of a reformer, an SOFC, and a recycle blower was constructed, assuming plug flow. Transient behavior of the system was analyzed where the increase of output power in accordance with the stepwise increases in required current and fuel supply was assumed. As a result of the analysis, the transient response of the AGR-SOFC was classified into three types according to the way of increase in the current and the fuel supply and characteristics of each type of responses are clarified. It was also found that the AGR-SOFC can increase the current and fuel supply more instantaneously and to a greater extent compared to conventional non AGR systems under identical fuel utilization conditions and superior output response is expected.