CFD Modeling of Stack-Integrated Autothermal Reformer and Solid Oxide Fuel Cell for High-Power-Density Applications

Coupling inline autothermal reformers (ATR) and air heat exchangers (HX) within solid-oxide fuel cell (SOFC) stacks provides a compact solution for integrating SOFCs into methane-fueled gas-turbine cycles. This study utilizes computational fluid dynamics to investigate the integrated ATR and air-preheating HX within an SOFC stack. For integration with gas-turbine cycles for aviation or ground power, the system employs controlled bleed air and anode exhaust recycling to drive the ATR. Simulations of the integrated ATR/HX/SOFC at 5.0 bar for a range of bleed air and anode recycle ratios reveal that a short-residence-time ATR can preheat the compressor air entering the HX at 400 °C to SOFC inlet temperatures over 600 °C for yttria-stabilized zirconia (YSZ) electrolyte cells and over 500 °C for gadolinium-doped ceria (GDC) electrolyte cells. Results show that the inline ATR produces CH 4 -H 2 mixtures into the SOFC anode that support power densities exceeding 1.0 W cm −2 with internal CH 4 reforming for stack thermal management. The superior ionic conductivity of the GDC electrolyte can sustain higher power densities at conditions with maximum temperatures below 680 °C, but the GDC cells require higher excess air ratios to mitigate electronic leakage. This study highlights the potential of the integrated ATR/HX/SOFC architecture for methane-fueled gas turbine systems.