Numerical Modeling and Simulation of the Solid Oxide Cell Stacks and Metal Interconnect Oxidation with OpenFOAM

Abstract

Solid oxide cells are capable of efficiently converting various chemical energy carriers to electricity and vice versa. The urgent challenge nowadays is the faster degradation rate compared with other fuel cell/electrolyzer technologies. To understand the degradation mechanisms, simulation of a solid oxide cell is helpful. Since most previous research developed models using commercial software, such as COMSOL and ANSYS Fluent, a gap for knowledge transfer is being gradually formed between academia and industry due to licensing issues. This paper introduces a multiphysics model, developed by a computational code, openFuelCell2. The code is implemented with an open-source library, OpenFOAM. It accounts for momentum transfer, mass transfer, electrochemical reactions and metal interconnect oxidation. The model can precisely predict I–V curves under different temperatures, fuel humidity and operation modes. Comparison between OpenFOAM and COMSOL simulations shows good agreement. The metal interconnect oxidation is modeled, which can predict the thickness of the oxide scale under different protective coatings. Simulations are conducted by assuming an ultra-thin film resistance on the rib surface. It is revealed that coatings fabricated by atmospheric plasma spraying can efficiently prevent metal interconnect oxidation, with a contribution of only 0.53 % to the total degradation rate.

High Temperature Solid Oxide Electrolysis – Technology and Modeling

“…Other approaches to couple reaction rate and activation overpotential are the Chang-Jaffe ´equation [62][63][64], assuming a linear dependency between activation overpotential and current [65,66], or the approach presented in [67] and applied by [68,69]. [70,71] apply an elementary step description for the fuel electrode and BV equation for the oxygen electrode.…”

“…The formation of an oxide layer on the IC surface is described by an interfacial ASR that increases over time [151,260,261] or by introducing an additional potential drop [66]. A transient term for the thickness of the layer is divided by the conductivity of the oxide layer that determines the additional resistance.…”

A Three-Dimensional Time-Dependent Model of the Degradation Caused by Chromium Poisoning in a Solid Oxide Fuel Cell Stack

“…The model considers one channel of the F10 SOFC stack in FZJ [21]. The geometry is shown in Figure 1, the details of which can be found in [22]. On the fuel side, a Ni mesh is chosen as the gas distributor.…”

“…The numerical model in this work is an extension of our previous work, where a steadystate model was developed [22,23]. By adding a degradation model of chromium poisoning, the model becomes time-dependent.…”

“…Only the governing equations and parameters related to chromium poisoning are presented in this work. Information about the steady-state model and parameters of the material properties, such as the conductivity and porosity of the electrodes, can be found in [22].…”