Case Studies in Thermal Engineering, vol.61, 2024 (SCI-Expanded)
Solid oxide fuel cells (SOFC) provide energy production at high temperatures. In this study, the effect of operating temperature (873 K–1673 K) and pore diameter (4 μm–16 μm), which are important parameters determining the performance of solid oxide fuel cells, are investigated by energy and exergy analysis. Quadrupling the pore diameter increases the activation loss by 0.280 V under constant current density. Thermal efficiency, exergy dissipated, entropy production and exergy efficiency are calculated using energy and exergy analysis. The power density increases with increasing temperature. For example, at a current density of 3000 A/m2, increasing the operating temperature by 45 % from 873 K increases the power density by 3.79 times compared to the initial case. At the same current density, when the pore diameter is 4 μm and 10 μm, the power densities are 2659.64 W/m2 and 2253.46 W/m2, respectively. This is explained by the high cell losses at low temperatures. At a current density of 1000 A/m2, the exergy dissipated is 719.85 kW at an operating temperature of 973 K and 1030.07 kW at 873 K. At 1073 K operating temperature and 7 μm pore diameter, the maximum thermal and exergy efficiencies are 67.77 % and 61.72 %, respectively. Increasing the operating temperature from 873 K to 1273 K increases the thermal and exergy efficiency by 31.55 % and 28.39 % respectively. Increasing the pore diameter decreases the power density and causes a decrease in thermal and exergy efficiency. Increasing the pore diameter by 30 % at a current density of 7000 A/m2 results in a decrease in thermal and exergy efficiency by 5.1 % and 4.64 %, respectively. This research examines the effects of different temperatures and pore diameters in detail by considering the exergy analysis of the solid oxide fuel cell with a thermodynamic approach, unlike the numerical analysis studies concentrated on in the current literature.