Emergency shutdown management in fuel cell gas turbine hybrid systems

A real-time dynamic model representing the pressurized fuel cell gas turbine hybrid system emulator test rig at Thermochemical Power Group (TPG) laboratories of the University of Genoa has been developed to study the fuel cell behavior during different critical operative situations like, for example, load changes (ramp and step), start-up and shut-down and, moreover, to implement an emergency shutdown strategy in order to avoid any damage to the fuel cell and to the whole system: focus has been on cathode/anode differential pressure, which model was validated against experimental data. The real emulator plant (located in Savona University campus) is composed of a 100 kW recuperated micro gas turbine, a modular cathodic vessel (4 modules of 0.8 m3 each) located between recuperator outlet and combustor inlet, and an anodic circuit (1 module of 0.8m3) based on the coupling of a single stage ejector with an anodic vessel. Different simulation tests were carried out to assess the behavior of cathode-anode pressure difference, identifying the best control strategies to minimize the pressure stress on fuel cell stack.