Thermodynamic analyses of a micro scale hybrid cycle of solid oxide fuel cell and micro-gas turbine

In the present paper, a hybrid cycle combing two novel technology of solid oxide fuel cell (SOFC) and micro gas turbine (MGT) to produce power in micro scale. The SOFC utilizes an external steam reformer to convert methane to hydrogen which is consumed as the SOFC main fuel. The fuel cell stack gas with high quality is used in a MGT to increase the cycle capability to produce more power. To analyze the cycle behavior a thermodynamic model is proposed and solved. In addition to make sure about the SOFC operation the cell voltage of the SOFC is calculated versus the current density and the calculated data is compared with experimental data presented by other researchers. The comparison shows a good agreement. To evaluate the cycle operation the impact of different parameters such as current density, cell working pressure and reforming temperature on the cycle performance criteria such as power generation by the SOFC, power generation by the MGT, cycle electrical efficiency, SOFC electrical efficiency, and SOFC working temperature are investigated. The results show that the fuel saving ratio of 45% in power production and overall electrical efficiency of 60% are achievable.