Influence of convective heat transfer by air flow on local current/temperatures along microtubular solid oxide fuel cells in-situ identified by electrode-segmentation method for Co- and counter-flow configurations

Contribution of spatial temperature variations to thermo-mechanical stresses along microtubular solid oxide fuel cells is often numerically estimated with local temperatures calculated by thermo-electrochemical models. This method is preferred due to the lack of experimental data. Not only to provide experimental data but also to reduce the temperature variations, in this paper we are analyzing the in-situ measured local temperatures and currents along a cell. We have measured the local properties by electrode-segmentation method for co- and counter-flow configurations at various air flow velocities. Gas flow configuration shows a substantial impact on both longitudinal temperature and current variations. Under the identical conditions, the counter-flow exhibits larger variations in both temperatures and currents. We conclude that air flow velocity determines the longitudinal temperature distributions, whereas its effect on the current distribution profile is negligible. With these findings, we anticipate larger thermo-mechanical stresses in the counter-flow configuration at high air flow velocities.