Solid oxide fuel cell and advanced combustion engine combined cycle: A pathway to 70% electrical efficiency

A computational system optimization was conducted to explore the efficiency potential of an electrochemical-combustion combined system for distributed power generation. A solid oxide fuel cell model was developed and validated to simulate the electrochemical conversion process and a zero dimensional model was implemented to simulate the engine combustion process. A system level approach was used to evaluate the trade-offs and efficiency potential of the system. A design of experiments of simulations was conducted to explore the design space and a genetic algorithm was used to search the resulting response surface for optimal operating conditions. Metal engine experiments were used to validate that the internal combustion engine is capable of operating under the desired operating conditions and the results were used to obtain final system efficiencies. The results showed that under fully homogeneous and stratified engine conditions the system is capable of achieving electrical efficiencies of 70% (LHV) at a 1 MWe power level while producing minimal soot and NOx emissions.