Thermodynamic Modeling of Power Plants Based on Solid Oxide Fuel Cells

A mathematical model of a solid oxide fuel cell is presented for investigation of the thermodynamic cycles of power plants. The model is one-dimensional in two directions: in the direction of fuel flow in the supply channel and perpendicular to the contact planes of the electrolyte and electrodes. Electrochemical reactions are assumed to run in the area of nonzero width adjoining the electrolyte. Natural gas is taken as a fuel, and its internal steam conversion in a porous anode is considered. Heat transfers are governed by the model of a generalized heat exchanger, described by accumulation curves of temperature-versus-power for heat sources and sinks. A binary plant with a fuel cell at atmospheric pressure and a subatmospheric gas-turbine bottoming is considered as an example.