Analysis of a simple solid oxide fuel cell system with gas dynamic in afterburner and connecting pipes

A simple solid oxide fuel cell plant is analysed based on the first law of thermodynamics approach. This system consists of a solid oxide fuel cell stack, a steam reformer, a mixer, a vaporiser, an afterburner, and two pre-heaters. To simplify the study, the enthalpy at each node of the system is normalized with the lower heating value of the inlet fuel. A gas dynamic model for calculating the flow in the pipes connecting the system components is considered and can be used to estimate the flow velocity and friction-induced pressure drop in the piping. Though the effect of a friction-induced pressure drop can be significant in a sizeable integrated,p solid oxide fuel cell-gas turbine power plant, it does not significantly, affect the plant efficiency in this study, due to rather short piping used in this simple power system. A steady flow energy equation and the Rayleigh line flow assumption are applied to the afterburner to calculate the exit flow temperature, velocity and pressure.