Dynamic Modeling of Reversible Solid Oxide Cells

Abstract

Reversible solid oxide cells (rSOCs) are highly efficient devices, which allow either the generation of electric power or the storage of energy via fuel production. In this paper, the characteristics of the mode switch are investigated by applying a dynamic 3D stack model. The responses of temperature, current density, and species mole fractions regarding a switch from storage (SOEC) to generation mode (SOFC) are examined in detail. Additionally, the impact of using excess air and continuous voltage variations to limit temperature gradients and fluctuations during the mode switch are analyzed.

Analysis of a biogas-fed SOFC CHP system based on multi-scale hierarchical modeling

“…The kinetic model was calibrated with i-V curves of an anodesupported single cell (Ni/YSZ-YSZ-LSM /YSZ) measured by Ebbesen et al [39] at operating temperatures of 1023.15 K and 1123.15 K with various fuel mixtures (H 2 /CO/CO 2 /H 2 O/Ar) in our previous paper [40]. The calibrated kinetic model was then used in stack simulations.…”

Integrated Multiscale Modeling of Solid Oxide Electrodes, Cells, Stacks, and Systems

“…The integrated multiscale model framework has been described in detail in my group's previous publications [3][4][5][6][7][8][9] and is only summarized here. In essence, the framework comprises of individual sub-models that provide continuum descriptions of the relevant physico-chemical phenomena at the multiple time and length scales involved.…”

“…They are particularly appealing for decentralized utilization of intermittent renewable energy as they are capable of both energy generation and storage. However, we found that the switch between endothermic electrolysis mode and exothermic fuel cell mode is particularly challenging for SOC stacks [6] due to the significant spatial and temporal gradients that manifest because of the mode switch (see Fig. 4).…”

“…Exploded view of 3‐D temperature profiles for a 50‐cell rSOC stack with a constant boundary temperature of 1023.15 K and feed gas composition of 50 % H 2 and 50 % H 2 O. At 7000 s, the stack was switched from endothermic electrolysis operation at 1.2 V to exothermic fuel cell operation at 0.7 V 6.…”

Distributed and Lumped Parameter Models for Fuel Cells

“…The effect of mass transport in a thick electrode has been analyzed by [43] in a two-dimensional study that couples mass and heat transport and included methane/steam reforming by means of a catalytic chemical reaction. Basically, in three-dimensional analysis, the governing equations for conservation of mass, momentum, species, thermal energy, electric charge, and electrochemical kinetics in anode and cathode of a SOFC are the same as those of a PEMFC, except that water transport through the electrolyte is not considered [44]. Orthogonal meshes are typically used in modeling planar SOFCs.…”