Steady-state multiplicity in a solid oxide fuel cell

Steady-state multiplicity in a solid oxide fuel cell (SOFC) in constant ohmic external load, potentiostatic, and galvanostatic operation modes is studied using a detailed first-principles lumped model. The SOFC model is derived by accounting for heat and mass transfer as well as electrochemical processes taking place inside the fuel cell. Conditions under which the fuel cell exhibits steady-state multiplicity are determined. The effects of operating conditions such as the convection heat transfer coefficient, and the inlet fuel and air temperatures and velocities on the steady state multiplicity regions are studied. Depending on the operating conditions, the cell exhibits one or three steady states. For example, it has three steady states at low external load resistances in the constant ohmic external load mode, and at low cell voltages in the potentiostatic mode.