Fuel Variation in a pressurized SOFC

Abstract

The demand for electrical energy is growing continually. In order to meet this demand in future, power plants with high efficiency and low emissions are needed. For example a hybrid power plant consisting of an SOFC system combined with a gas turbine which offers electrical efficiencies of up to 60% at a wide range of applications from kW to MW. One major advantage of this combination is that it can be operated amongst others on natural gas from the existing grid. Efficiencies have been shown to be highest if the SOFC subsystem is pressurized. This and the requirements due to the interaction with the gas turbine lead to a need to exactly understand the behavior of SOFC at elevated pressures. The German Aerospace Center (DLR) is aiming to demonstrate stable operation of such a hybrid power plant and is currently examining the behavior, requirements and limits of the subsystems at elevated pressure. A test rig for the examination of pressurized SOFC exists at DLR to examine various planar stack designs at elevated pressure which has so far been used to asses the influence of pressure on performance with different fuels at different temperatures as well as operational limits at elevated pressures. Experimental results have been used for validation of a cell model which allows for a thorough interpretation of the experimental data. This contribution summarizes the advances made within the last years concerning the experimental examination and the complementary simulation of pressurized SOFC at DLR