System level performance analysis and parameter optimization of hydrogen production based on solid oxide electrolytic cell

The high-temperature solid oxide electrolytic cell (SOEC) is expected to be widely used in large-scale energy storage, the chemical industry, distributed energy, and other fields due to its high efficiency and cleanliness. Moreover, selecting the operation point of the SOEC system with variable load under high-temperature conditions and striking a balance between safety and efficiency are difficult. Therefore, a 3 kW SOEC system model is built following the electrochemical reaction principle and the considered system layout. Based on this, the influence of operating parameters on stack voltage and power, stack outlet temperature, system H2 production, specific energy consumption, system efficiency, and the power consumption distribution of auxiliary equipment are analyzed. Finally, the operating current, temperature, air flow, and H2O utilization rate were taken as optimization variables, and the safe range of operating parameters was taken as the constraint condition to optimize system efficiency. The results show that under the given operating conditions and assumptions, the energy efficiency of the SOEC system can be adjusted from 60 % to 100 %, and the temperature difference can be controlled within 100 ℃. The durability of the system is improved by maximally reducing the temperature difference while ensuring the high efficiency of reactor operation.