Application Simulation of SOFC-CHP Systems

To find the most suitable system process for SOFC stacks with different fuel utilization rates(U_f), so as to meet the requirements of different stacks and users on the system output, three different models were set up for 1 kW SOFC combined heat and power (SOFC-CHP) systems by Aspen Plus, including the cathode/anode exhaust gas combustion system, anode off-gas recycling system, and combined anode off-gas recycling system with exhaust gas combustion. Results show that the cathode/anode exhaust gas combustion process is a preferred option for SOFC stacks with relatively high U_f. Both the anode off-gas recycling process and the combined anode off-gas recycling process with exhaust gas combustion are preferred options for SOFC stacks with relatively low U_f; however, to achieve relatively high heat efficiency on the basis of ensuring high power efficiency, the combined anode off-gas recycling process with exhaust gas combustion is the optimal option.