Computational analysis of operating temperature, hydrogen flow rate and anode thickness in anode-supported flat-tube solid oxide fuel cells

Flat-tube solid oxide fuel cells (FT-SOFCs) are advantageous because of their easy sealing, low stack volume and low resistance to current collection. The performance of FT-SOFCs is determined by the electrochemical reaction, which is closely linked to the heat and mass transfer inside the cell. Therefore, both the electrochemical reaction and the transport phenomena are investigated in this study using a numerical approach. Numerical results are evaluated by physical property models, governing equations and electrochemical reaction models. After simulation, the results are compared with experimental data for code validation, and the current density and the temperature are presented as numerical results. The FT-SOFC performance improves with a higher operating temperature due to the activated electrochemical reaction. If the cell support is thickened in order to achieve higher mechanical strength, the mass transfer rate is reduced and the ohmic polarization increases. These phenomena can lower the performance. Increasing the amount of hydrogen provides a higher mass transfer rate; therefore, the FT-SOFC can obtain a higher and a more uniform current density distribution.

► The parametric study for flat-tube solid oxide fuel cells was carried out using a numerical analysis.
► A single cell having 13 channels and an active area of 37.2 cm2 was used for the validation experiment and the simulation.
► The performance at 750 °C was 45% higher than that at 650 °C because the high temperature activates electrochemical reactions.
► The average current density for a hydrogen stoichiometry number of 1.5 was 3412.8 A/m2.
► The single cell with an anode thickness of 5.2 mm showed 2686.1 A/m2, which was 22% lower than that of 3.2 mm.