Electrochemical performance investigation of solid oxide fuel cell in micro-gas turbine hybrid systems to determine optimum fuel utilization factor

The present study was undertaken to design and analyze three different configurations of SOFC (solid oxide fuel cell) and MGT (micro-gas turbine) hybrid system. The first presented configuration is a hybrid system with one fuel cell which considered as a basic mode. Two other configurations are considered with two fuel cells that mounted upstream of the turbine in series and parallel forms. The aim of the current study was thermodynamic analyze of designed hybrid systems and achieving the optimum fuel consumption factor for fuel cells that used in hybrid systems. Therefore¡ other performance parameters such as turbine inlet temperature¡ compressor pressure ratio and the number of cells¡ which play an important role in implementation of SOFC and gas-turbine¡ were parametrically analyzed and the obtained optimum values were used in analyzes. In this regard¡ the parameters associated with electrochemical processes within cells considered as a function of their chemical and thermodynamic conditions¡ and their modeling code combined with the modeling code of micro gas turbine cycle. The results of this study revealed that fuel utilization factor has direct impact on the SOFC/MGT hybrid system performance. Also we demonstrate that the optimal fuel utilization factor for basic mode hybrid system was 0.85¡ hybrid system with 2 series fuel cells were obtained 0.7 and 0.8 respectively and hybrid system with two parallel fuel cells were calculated to be 0.85. Moreover¡ the SOFC/MGT hybrid system with two series fuel cells account for the highest electrical efficiency and was selected as the most efficient configuration.