Numerical performance analysis of the solid oxide fuel cell for aviation hybrid power system

A detailed three-dimensional model of solid oxide fuel cell (SOFC) is established to explore its performance under special requirements in the aviation SOFC - gas turbine hybrid system. In this context, the SOFC has the distinction of pressurization, lightweight and low pressure loss compared to its conventional independent application. Based on this, the SOFC performance is fully investigated in terms of different operating conditions and geometric dimensions, and in addition to typical electrochemical parameters, the power-to-weight ratio is also considered as evaluation indicator. The results indicate that high operating pressure is beneficial for improving SOFC electrochemical performance, but the performance enhancement becomes slow when pressure exceeds 0.5 MPa. The inlet velocities of fuel and air both affect fuel utilization and power density of SOFC. And the high air velocity is favorable to reduce the SOFC temperature and temperature gradient, but it also increases the pressure drop. Therefore, the air inlet velocity of 2 m/s-15 m/s is more suitable under comprehensive consideration. In addition, the optimal power density and power-to-weight ratio correspond to different rib widths, with the former having wider ribs and differing within 0.5 mm. And this characteristic is maintained at different pressure, contact resistance and interconnect density.