Numerical simulation of molten carbonate fuel-cell power-generation systems

This paper provides a dynamic simulation model for investigation of the characteristics of molten carbonate fuel cell (MCFC) systems. To achieve the accuracy of the system model, the essential component model (i.g. fuel cell stack) is first established in three-dimensional, dynamic form, and it is then simplified prior to incorporation into the system model. The development of simulation techniques, such as estimation of variable limits, connection between component models, definition of input variable variation, and selection of simulation time step, has resulted in successful simulations. The stationary simulation results for the entire load range show that the fuel cell system has the highest efficiency at partial load (45% full load). The dynamic simulation results indicate the existence of dynamic interactions between the stack and reformer under load-up operation. Moreover, the investigation has evaluated the alternative operation strategy of providing fuel gas directly to the reformer combustor during load-up mode. This alternative strategy has significantly reduced the dynamic interactions. The model has also been used to select the location of the fuel flow control valve. These results can be used to improve MCFC system operation and control design.