At Thermochemichal Power Group (TPG) laboratory, a test rig, partially supported by PIP-SOFC European contract, has been developed to investigate the performance of ejectors for SOFC applications, with the objective to validate the theoretical models and improve the ejector design. At first, the prototype, presented in the previous paragraph, has been tested in classical open loop configuration with the secondary nozzle at atmospheric conditions, feeding the primary duct with compressed air and using a valve to generate different values of differential pressure on the ejector. The plant has been equipped with transducers to measure the mass flow rate, the pressure and the temperature upstream the primary nozzle, the mass flow rate at the diffuser outlet (using a venturimeter) and the differential pressure between the secondary duct inlet and the diffuser outlet. The transducers signals have been connected with a PC, through a PCI device, and acquired using the LabVIEWTM software.
Then, the circuit has been closed introducing a vessel to emulate, in a reduced scale, the anodic volume of the SOFC and an another valve to vary the circuit pressure loss with the requested accuracy level. In this way, through a manual outlet valve, it has been possible to study ejectors at secondary flow pressurized conditions, acquiring also the vessel pressure with another apt transducer. Finally, the plant has been equipped with an electrical heater inside the vessel and thermally insulated to test ejectors with a secondary flow up to 300°C. Even if this temperature is lower in comparison with its operative real value (~ 900 °C), it is enough to reach the similitude conditions that have been considered.
