Analysis of the Interaction Between Cathode and Anode Sides With a Hybrid System Emulator Test Rig

The TPG research group of the University of Genoa designed and installed a complete hybrid system emulator test rig equipped with a 100 kW recuperated micro gas turbine, a modular cathodic vessel located between recuperator outlet and combustor inlet, and an anodic circuit based on the coupling of a single stage ejector with an anodic vessel. The layout of the system was carefully designed considering the coupling between a planar SOFC stack and the 100 kW commercial machine installed at TPG laboratory. A 450 kW direct-fired pressurized hybrid system was studied to define the anodic side properties in terms of mass flow rates, pressures, and temperatures. In this work, this experimental facility is used to analyze the cathodic/anodic side interaction from fluid dynamic and thermal point of view. Even if the tests carried out with this rig were produced with an ejector based anodic recirculation, results shown here for the cathode/anode interaction tests can be considered general not dependent on recirculation technology. Attention is mainly focused on the cathode/anode differential pressure value in both design and off-design conditions. For this reason, a wide experimental campaign was carried out to measure the behavior of this property in different operative conditions with the objective to avoid pressure stress for the fuel cell stack. Furthermore, the interaction between the machine and the anodic circuit is studied and discussed in this work.