Effect of tube radius on creep for an anode supported tubular solid oxide fuel cell: Experimental and finite element simulation

In this study, we present a creep analysis for an anode-supported tubular solid oxide fuel cell (SOFC). The effects of tube radius on creep and stress are also studied. The as-sintered residual stress is measured by an X-ray diffraction instrument. Simulated result is consistent with the measurement data. The finding shows that the fracture starts in the electrolyte for the big tube radius after 50 000 h because of the mismatch creep properties between SOFC layers. As tube radius increases, the hoop stress in the electrolyte also increases because the growth of elastic strain is dominant compared with creep relaxation. Hoop stress in the electrolyte exceeds the tensile strength when the tube radius is larger than 30 mm for our SOFC system. The tube radius should be designed to be in millimeter level or sub-millimeter level to decrease the growth of hoop stress in the electrolyte and ensure long-term reliability at high temperatures.