Solid oxide fuel cell (SOFC) stack modeling

Modeling thermal cycling behavior in high-power density SOFC stacks (DETCHEMSOC + DETCHEMMONOLITH)

Simulating the start-up behavior of a 10 kWe-class high-power density metal-supported Ni-CGO/CGO/YSZ/CGO/LSCF-CGO 120-cell stack for stationary and mobile power generation. Shown is the temperature profile of the stack solid phase including a microporous silica-based insulation layer at the stack’s periphery. The model includes convective and radiative heat loss to the ambient surroundings. While the transient calculation starts at 0 minutes by initializing the solid phase temperature field at 373.15 K (cold stand-by mode), air is used as a heating medium for heating up the stack to its operating temperature at ~973.15 K with constant mass flow rate and linear temperature ramp as depicted in Fig. 1. Hydrogen fuel is fed to the fuel channels when the stack temperature reaches 873.15 K after ~67 minutes, where current starts to get drawn from the stack (Fig. 1).


Materials Synthesis

Production of advanced carbon materials by pyrolysis and chemical vapor infiltration

Numerical predicted temporal development of 2d spatial of density and species concentration profiles within in carbon felts. Based on multi-step reaction and deposition models including the hydrogen inhibition model of pyrocarbon growth, transient 2D simulations of chemical vapor infiltration of methane were carried out by a finite element method (FEM) coupling the mass transfer (by convection and diffusion) and the evolutive surface area model with gas-phase and surface chemical reactions. The continuous infiltration, pyrolysis and deposition of methane and its consecutive hydrocarbon products lead to continuously varying concentration and density inside the carbon felt.


High temperature catalysis

Transient behavior of partial oxidation monoliths (DETCHEM MONOLITH)

Light-off of an extruded monolith coated with rhodium as used for partial oxidation of methane to synthesis gas. A cold methane/oxygen/nitrogen mixture flows from left into the preheated cold monolith. The figures reveal the calculated temperature distribution of the monolith and the methane, hydrogen, and water concentrations within three single monolith channels after 2 and 120 seconds of reactor operation.


Automotive catalytic converters

Simulation of the thermal behavior of a three-way catalyst during a driving test (DETCHEM MONOLITH)

Light-off of an extruded monolith coated with rhodium as used for partial oxidation of methane to synthesis gas. A cold methane/oxygen/nitrogen mixture flows from left into the preheated cold monolith. The figures reveal the calculated temperature distribution of the monolith and the methane, hydrogen, and water concentrations within three single monolith channels after 2 and 120 seconds of reactor operation.


Flow field modeling

Modeling of flow field up and downstream of a monolith (DUO)

Two coupled flow domains using different turbulence models and numerical parameters have been solved. The pressure loss of each of the 1100 channels of the monolith (one quarter of catalyst assembly) was derived on basis of a developed laminar flow.


CPOX reactor modeling

Modeling of a CPOX (Catalytic Partial Oxidation) reactor (DUO)

Shown is the temperature field of the fluid part and the two solid bodies. The fluid part and solid regions are solved with OpenFOAM®. Flow and surface chemistry in the channels of the second monolith are calculated by DETCHEM.


Temperature field of the fluid part and the two solid bodies (only the second one is coated). Fluid part and solid regions are solved with OpenFOAM® whereas the detailed surface reaction is calculated by DETCHEM. Additionally, some streaklines are plotted. The slice at the end of the calculation domain shows the distribution of the velocity into z-direction.