CHAPTER 13: Integrated SOFC and Gas Turbine Systems
Published:16 Aug 2013
Solid Oxide Fuel Cells (SOFC) are particularly promising for their capability to be integrated in complex power plants, showing ultra-high conversion efficiencies. This chapter investigates some possible layout configurations of hybrid power plants including both SOFC and Gas Turbine (GT) technologies. SOFC/GT power plants have been diffusely investigated in literature, from both numerical and experimental viewpoints. Such systems are mainly fed by methane which can be reformed into hydrogen inside (internal reforming) or outside (external reforming) the stack. The majority of SOFC/GT hybrid systems use the internal reforming arrangement which allows one to minimize system capital cost. The steam required to drive the reforming reaction can be supplied by the anode recirculated stream. Alternatively, such steam can be produced externally, using the heat of the exhaust gases. SOFC/GT power plants can operate both in atmospheric and pressurized modes. The atmospheric plants are easier to manage due to the possibility to decouple SOFC and GT operations. On the other hand, pressurized SOFC/GT power plants show higher efficiencies. More complex SOFC/GT configurations are also analyzed, such as: SOFC/HAT turbines, IGCC SOFC/GT power plants, SOFC/GT Cheng cycles, etc. Finally, the chapter also presents the control strategies to be used in the managements of hybrid SOFC/GT power plants, also showing some results of the transient operation of these systems.