Zero-dimensional robust model of an SOFC with internal reforming for hybrid energy cycles

We present a mathematical model of a tubular solid oxide fuel cell (SOFC) and its implementation in an in-house zero-dimensional code named COM-GAS. The proposed zero-dimensional robust model of the SOFC with internal reforming for hybrid energy cycles allows the prediction of basic SOFC parameters such as current, voltage, voltage losses, combustion composition, power output, efficiency etc. The voltage generated by the SOFC was determined based on the extended Nernst equation. Exhaust gas composition was estimated based on equilibrium in the steady-state water gas shift reaction. Numerical simulations of both power output and voltage were compared with available experimental data, and differences did not exceed 5% in most cases. High efficiency, low emission, and fuel flexibility allows SOFCs to be coupled with gas turbines (GTs), representing a remarkable solution for hybrid cycles. In particular, when using the coupled SOFC/GT, the integrated hybrid cycle efficiency can be significantly increased (to 55%-58%) depending on its type. The newly-proposed double-pressurised SOFC/GT, not previously studied, can be used for applications requiring a low power range and low emissions.