Numerical simulation and analysis of the thermal stresses of a planar solid oxide electrolysis cell

High Temperature Solid Oxide Electrolysis – Technology and Modeling

“…One possibility is to extend the NSE with a Darcy's law term [52,53,57,62,65,86,91,137,138,[140][141][142][143]. [58,88,90,91,122,144,145] apply forms of Brinkman equation, while [60,71,79,146] replace NSE with Darcy's law and [83,147] rely on the implementation in the dusty-gas model. The permeability needed for the Darcy's law term is determined via the Kozeny-Carman equation [51,88,141,148,149].…”

“…Mainly DGM [42,51,54,55,60,77,83,85,86,92,132,147] or SMM, either neglecting Knudsen diffusion [143,146] or considering it with a Bosanquet formulation [58,62,88,148,177,178], is implemented. FM is applied without Knudsen diffusion [142] or with Bosanquet formulation [145,179] while the Convection-Diffusion equation is used either with [137,138] or without [139] Bosanquet formulation to describe species transport. For all models the coupling between mass flow rate through the electrodes, electronic and ionic current densities is described with Faraday's law assuming ideal Faradaic efficiency, side reactions do not have to be considered in SOCs.…”

“…In modeling of mechanical stress in SOCs, common and most simple assumption is an isotropic [52,144,179,191,193,214,215] and linear elastic [52,144,145,178,179,191,193,210,213] material behavior, as well as a linear and isotropic thermal strain [144,145,191,193]. In the case of homogenization approaches as in [178,213], the effective mechanical parameters for the homogenized materials become anisotropic.…”

“…In these investigations sealant, frame and cell were considered as one domain. [52,69,179,193,216] resolve the stress distribution in cell layers with [145] additionally including the IC and [144] the sealings. The impact of residual stresses in the different layers of a cell [216] or stack [213] was studied using Bernoulli-Euler beam theory.…”

“…Expanding the geometry to cover the whole cell area enables to investigate more complex serpentine [235] and alternative [132] flow field designs. In these full cell models, both co-flow [86,137] and crossflow [62,69,137,145,182,193] configuration can be studied.…”