Multi-objective optimization of a solid oxide fuel cell-based integrated system to select the optimal closed thermodynamic cycle and heat coupling scheme simultaneously.

Integrating thermodynamic cycles with SOFCs is an effective technology to make full use of energy, but the difficulty lies in selecting the optimum thermodynamic cycles and integration scheme. The performance of a thermodynamic cycle is directly determined by the working fluid and operating parameters, and the heat exchange network (HEN) synthesis scheme directly affects the heat coupling degree and the economic performance. Therefore, a multi-objective optimization model is proposed in this paper, where the working fluid and operating parameters of the closed cycle, as well as the HEN synthesis scheme are selected as decision variables, while the total exergy destruction (TED) and the total annual cost (TAC) are adopted as the objectives. To solve this complex problem, a solving strategy based on NSGA-II with two levels is proposed to obtain the Pareto Frontier of TED and TAC. Finally, a case is solved and three Pareto optimality are analyzed and compared. • An optimization model of the SOFC-based integrated system is established. • The closed thermodynamic cycle and the HEN synthesis are optimized simultaneously. • The total exergy destruction and the total annual cost are adopted as two objectives. • A solving strategy with two levels based on NSGA-II is proposed. [ABSTRACT FROM AUTHOR]