Full load synthesis/design optimization of a hybrid SOFC–GT power plant

• Published in: Energy (Oxford) 2007-04, Vol.32 (4), p.446-458
• Main Authors: Calise, F., Dentice d’ Accadia, M., Vanoli, L., von Spakovsky, Michael R.
• Format: Article
• Language: English
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exergy; Fuel cells; Installations for energy generation and conversion: thermal and electrical energy; Optimization; Other installations: mhd power plants, fuel cell plants, incineration plants, etc; Solid oxide fuel cell; Thermoeconomics
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2006.06.016

In this paper, the optimization of a hybrid solid oxide fuel cell–gas turbine (SOFC–GT) power plant is presented. The plant layout is based on an internal reforming SOFC stack; it also consists of a radial gas turbine, centrifugal compressors and plate-fin heat exchangers. In the first part of the paper, the bulk-flow model used to simulate the plant is presented. In the second part, a thermoeconomic model is developed by introducing capital cost functions. The whole plant is first simulated for a fixed configuration of the most important synthesis/design (S/D) parameters in order to establish a reference design configuration. Next a S/D optimization of the plant is carried out using a traditional single-level approach, based on a genetic algorithm. The optimization determined a set of S/D decision variable values with a capital cost significantly lower than that of the reference design, even though the net electrical efficiency for the optimal configuration was very close to that of the initial one. Furthermore, the optimization procedure dramatically reduced the SOFC active area and the compact heat exchanger areas.