Study on the operating parameters of the 10 kW SOFC-CHP system with syngas

Solid oxide fuel cell combined with heat and power (SOFC-CHP) system is a distributed power generation system with low pollution and high efficiency. In this paper, a 10 kW SOFC-CHP system model using syngas was built in Aspen plus. Key operating parameters, such as steam to fuel ratio, stack temperature, reformer temperature, air flow rate, and air preheating temperature, were analyzed. Optimization was conducted based on the simulation results. Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency, but it might decrease the gross system efficiency. Higher stack and reformer temperatures contribute to the electrical efficiency, and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750 °C and 700 °C, respectively. The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency, the recommended value is around 600 °C under the reference condition.