Numerical investigation of combustion and flame characteristics for a model solid oxide fuel cell performance improvement

•Solid oxide fuel cell-combustion hybrid system has been considered.•Colorless distributed combustion provided a more uniform thermal field.•A more uniform thermal field enabled higher fuel cell power density.•A more uniform thermal field increased hydrogen consumption rate. This paper applies computational fluid dynamics techniques to investigate the flame characteristics in the afterburner of a model solid oxide fuel cell system. The main objective of this research is to analyze the flame characteristics to serve as a reference for performance improvement of the model solid oxide fuel cell. The generated swirl burner was modelled under conventional and colorless distributed combustion conditions. It is because recommended for obtaining a more uniform temperature distributions over the entire of the combustor, resulting in far enough temperature levels for the best performance of the fuel cell. In order to achieve distributed regime during methane combustion, oxygen concentration in the oxidizer was reduced through entrainment of the diluent mixture (90% N2 and 10% CO2). The parameters affecting the performance of a model solid oxide fuel cell were also numerically investigated. The temperature zones obtained from combustion were used to initiate and sustain the solid oxide fuel cell. Cell performance values for different temperatures were analyzed and interpreted. The maximum power value was obtained under distributed regime. While the maximum power points of the cells were gathered in the high performance region at 15% O2, lower power values were obtained at 21% O2 content.