Fluid dynamics parameters of a high temperature ejector for SOFC anode gas recirculation

Abstract

The energy sector embraces solid oxide fuel cells (SOFC) since they are highly efficient and ecologically sound power generators. Yet, maintaining fuel cells sustainability in power units takes a lot of resources. Hence, we need to find the appropriate ways to increase the efficiency of the whole SOFC power system inclusive of its balance-of-plant equipment. This can facilitate our fuel and energy complex green transition through the SOFC technology introduction. As a matter of fact, anode gas recirculation is instrumental for boosting the SOFC power units efficiency. One of the challenges in developing the SOFC power unit with anode gas recirculation is to return the amount of anode gas appropriate for carbon deposition free reforming. The paper contains the anode gas recirculation ratio in the SOFC power units calculation method for various reforming temperatures. The safest operation modes of the SOFC power units with anode gas recirculation were determined. The 3 kW SOFC power unit with high temperature ejector and nickel-based catalyst for methane conversion was designed. For the given flow channel geometry, the high temperature ejector off-design performance was plotted. In addition, fields of temperature, pressure and velocities were plotted for the ejector design point using Ansys computational fluid dynamics software.