Parametric Study of Combining Single and Double stages Solid Oxide Fuel Cell with Gas Turbine

In this paper, a parametric study is done to reveal the effects on the performance of the single and double stages solid oxide fuel cell/ gas turbine combined systems of such significant parameters as fuel cell operating temperature, fuel utilization factor and current density. The behavior of tubular solid oxide fuel cell modeled in this study is validated with the experimental test data of tubular SOFC developed by Siemens Westinghouse. According to parametric study, the high value of first law efficiency of the double stage SOFC-GT combined cycle occurs when the operating temperature of the first and second fuel cell stacks is 1180 and 1250 ˚C, respectively; but the highest value of net output power occurs in higher temperatures of the second fuel cell stack. In the constant current density of the fuel cell, increasing the fuel utilization factor of the fuel cell decreases the voltage losses of the fuel cell and causes to decrease of the exergy destruction of the combined cycle.