Fuel Cell & Electrolyzer Module Updates
For users of the Fuel Cell & Electrolyzer Module, COMSOL Multiphysics® version 6.3 introduces a new interface to model transport in any electrolyte solution, improved features and variables for two-phase flow, and new capabilities for parameter estimation. Read more about these updates below.
Concentrated Electrolyte Transport Interface
A Concentrated Electrolyte Transport interface is now available for modeling transport in any electrolyte solution with an arbitrary number of charged and uncharged species. This electrochemistry interface is based on concentrated solution theory, where the transport equations are defined using binary Maxwell–Stefan diffusion coefficients assuming local electroneutrality. In contrast to the Nernst–Planck equations, the concentrated solution theory does not assume the electrolyte species to be diluted in a neutral solvent of constant concentration. Typical electrolytes that can be modeled include ionic liquids, salt melts, and highly concentrated solutions featuring nonnegligible concentration gradients of the charge-carrying species. The new Molten Carbonate Transport tutorial model showcases this functionality.
Parameter Estimation
The Parameter Estimation study step and the BOBYQA, Levenberg–Marquardt, and IPOPT optimization solvers are now available in the Fuel Cell & Electrolyzer Module. Parameter estimation is used for determining model parameters by fitting simulations to experimental data. The Parameter Estimation of a Polymer Membrane Fuel Cell Model tutorial model demonstrates this new addition.
Improved Features and Variables for Two-Phase Flow
The Hydrogen Fuel Cell and Water Electrolyzer interfaces now include the ability to define mass sources in the liquid and gas phases, both on boundaries and in domains, via coupling to features that have been added to the Phase Transport interface in version 6.3. Mass source terms can be added on boundaries using the new Boundary Mass Source feature and in domains using the new Mass Source feature.
In the Hydrogen Fuel Cell and Water Electrolyzer interfaces, Solid and Liquid phase options are now available for the Electrolyte type. This feature specifies whether the charge-carrying ion contributes to the liquid mass flux and source variables defined by the interface. Additionally, in the Model Wizard, Alkaline entries have been added that use the Liquid option by default. The following tutorial models showcase these improvements:
- two_phase_pemfc
- zero_gap_aec
- aec_shunt_currents (Alkaline option only)
Shear-Induced Migration in Dispersed Multiphase Flow
In concentrated suspensions, irreversible particle collisions lead to particle migration toward regions with lower shear rates, a phenomenon used in processes like particle fractionation and microfiltration. For example, in pressure-driven channel flow of a neutrally buoyant mixture, particles tend to aggregate at the center of the channel. A new Include shear-induced migration option, now available in the Mixture Model multiphysics coupling, supports multiple species and enhances the accuracy of such simulations.
Power Law Option for Relative Permeabilities
The Porous Medium feature in the Phase Transport in Porous Media interface now includes a new Power law option, making it easier to implement relative permeabilities based on power law expressions. This enhancement simplifies the setup and modeling of permeability behavior in porous media simulations.
Result Templates in the Chemical Species Transport Interfaces
Creating useful and visually appealing plots of reacting systems can be time consuming since there are often many reactants and thus many concentration fields to plot. To save time, there are a number of new Result Templates in the Chemical Species Transport interfaces. Among these, plot array templates are now available that include up to four species concentrations simultaneously in the Graphics window. The Result Templates are available for all Chemical Species Transport interfaces, independent of the add-on product, but are especially useful for the multicomponent transport interfaces included in the modules for chemical engineering as well as in the CFD Module, Porous Media Flow Module, Subsurface Flow Module, and Microfluidics Module.
New Tutorial Models
COMSOL Multiphysics® version 6.3 brings several new tutorial models to the Fuel Cell & Electrolyzer Module.
Two-Phase Nonisothermal Zero-Gap Alkaline Water Electrolyzer
Water and Carbon Dioxide Co-Electrolysis in a Solid Oxide Electrolyzer Cell
Ammonia-Fed Solid Oxide Fuel Cell
Two-Phase Polymer Electrolyte Membrane Fuel Cell
Parameter Estimation of a Polymer Electrolyte Membrane Fuel Cell Model
Molten Carbonate Transport
