Solid oxide fuel cell (SOFC) has attracted more and more attention due to its power generation characteristics of high efficiency, low emission, and strong fuel adaptability. In order to ensure the stable and efficient operation of the system, it is urgent to study the thermoelectric characteristics and control laws of SOFC systems under different fuels for different fuel types can result in different thermoelectric characteristics. Therefore, based on the 200-hour experimental data obtained from an external steam-reforming SOFC independent power generation system, the temperature distribution and electrical characteristics of the system at different power stages are studied. Moreover, the thermoelectric characteristics of the independent SOFC systems under pure hydrogen and methane fuel types with the same output power are further compared. The results show that, the stack voltage and the fuel utilization rate of the methane fed SOFC system is lower than that of the hydrogen fueled SOFC system. And the temperature gradient on the fuel side of the methane fed SOFC system is relatively large, while the temperature gradient on the air side of the hydrogen fueled SOFC is relatively large. The analysis process plays a significant role in system control strategy design, which improves the fuel adaptability of the system.
Keywords solid oxide fuel cell, temperature distribution, electrical characteristics, temperature gradient