Comparison in behaviors of anode-supported and metal-supported solid oxide fuel cell systems during hot start-up process

To shorten the start-up time of solid oxide fuel cell (SOFC), the mathematical models are established for the 60-kW AS-SOFC and MS-SOFC and the hot start-up behaviors are compared. The results indicate that the two systems can achieve the rated power within 3 min. The temperature change rate of the stack in the AS-SOFC and MS-SOFC are −15.8–14.4 K/min and −11.9–13.3 K/min, respectively. Benefit from the high mechanical strength of the metal support, the temperature change rate of the MS-SOFC is acceptable whereas there is a risk of failure for the AS-SOFC. At the rated power point, the hydrogen flow rate supplied to the anode and the afterburner of the MS-SOFC is significantly less than that of the AS-SOFC. Moreover, the areas and wall temperatures of the heat exchangers in the MS-SOFC system are much smaller, making the MS-SOFC more suitable for applications with rigid requirements on size and cost.