Investigation of the performance of cathode supported solid oxide fuel cell with energy and exergy analysis at different operating temperatures

Abstract

In this research, the performance analysis of a cathode-supported solid oxide fuel cell (SOFC) with an active cell area of 0.0834 m2 and a cathode thickness of 750 µm was carried out under three different operating temperatures (973 K, 1073 K and 1173 K). The power density and cell potential were calculated by determining the losses in the cell at 8 different current densities (1500 A/m2 - 5000 A/m2) for each operating temperature. It was observed that ohmic losses in SOFC have a lower effect on the cell potential compared to other losses. An increase of the operating temperature by 100 K resulted in a decrease in ohmic losses of 3.36×10-8 V under constant current density (CD). In addition, the rise in CD negatively affected all the losses in the cell and decreased the cell voltage. The exergy and energy analysis of SOFC was carried out by calculating the thermal efficiency, exergy destruction, entropy production and exergy efficiency for various operating parameters. An increment of 200 K in the operating temperature increased the thermal efficiency by approximately 2 times at a CD of 5000 A/m2. Also, the minimum entropy production was obtained at an operating temperature of 1173 K and a CD of 1500 A/m2. In this case, the entropy production was calculated as 2.63 kW/K, resulting in a maximum exergy efficiency of 66.93%.