Numerical Analysis of Output Characteristics of a Tubular SOFC with Different Fuel Compositions and Mass Flow Rates

The purpose of this paper is to present a control volume based numerical model for simulation of fuel/air flow, electrodes, and electrolyte components of a single tubular solid oxide fuel cell. The SOFC uses a mixture of H-2, CO, CO2, and H2O (vapor) components (pre-reformed methane gas) as fuel. The developed model determines the effect of fuel and air mass flux on local EMF, state variables (pressure, temperature and species concentration) and cell performance. In addition, the effect of fuel hydrogen concentration on output characteristics of fuel cell is investigated. If we consider a pure hydrogen fuel, we will have maximum Nerenst potential and power generation. While the hydrogen goes through the channel and is being consumed, vapor is introduced into the flow and hydrogen concentration is reduced along the flow direction. Therefore, the local Nernst potential decreases. For mixed fuel, output parameters are function of fuel molar composition. In general, this model shows how output parameters of the SOFC can be controlled and adjusted by inlet fuel and air mass flow rate as well as hydrogen concentration of the fuel. Finally the numerical study is validated by experimental results such as polarization curve and power density.