Design and operation optimization of an internal reforming solid oxide fuel cell integrated system based on multi objective approach

The interaction between design parameters and operation variables is a complex problem that affects system techno-economic performance. The aim of this paper is to optimize the design and operation of an SOFC/MGT integrated system. The problem consists of design and operation optimization of an integrated SOFC/MGT system. Decision variables including design parameters (number of SOFC cells) as well as the operation parameters (air pressure ratio, methane and air flow rates). The multi objective approach using genetic algorithm is applied considering two pairs of proposed objectives: (1) maximization of output power and minimization of the electricity cost and (2) maximization of system electrical efficiency and minimization of the electricity cost. The results demonstrate minimum cost of electricity is 0.047$/kW h at 306.49 kW output power and 59.93% efficiency. The Pareto frontiers show that 11.23% growth of output power leads to only 5.3% increase in electricity cost and a growth of 12.18% increase of efficiency leads to only 4.05% increase in electricity cost, which is more favorable. Multi objective optimization provides valuable information about flexibility of trade-offs between design and operation variables for decision making and determination of system marginal cost.