ELECTROCHEMICAL FUEL CELL SYSTEM WITH A REGULATED VACUUM EJECTOR FOR RECIRCULATION OF THE FLUID FUEL STREAM

摘要

An electric power generation system has a regulated vacuum ejector for recirculating the fluid fuel stream. The system includes a fuel cell stack, a pressurized fuel supply having a pressure control valve for regulating the pressure of the fuel supply, a vacuum ejector interposed between the fuel supply and the stack fuel stream inlet, a pressure transducer interposed between the ejector discharge outlet and the stack fuel stream inlet, and a pressurized oxidant supply with a pressure transducer. The ejector suction inlet is fluidly connected to the fuel stream outlet of the fuel cell stack. The fuel stream pressure transducer transmits a signal to the pressure control valve to adjust the pressure of the fuel supply when the detected pressure of the fuel stream deviates from a predetermined value. The oxidant stream pressure transducer transmits a signal to the pressure control valve to adjust the pressure of the fuel supply when the detected pressure of the oxidant stream changes. The system is load-following to maintain uniform fuel stream pressure and recirculation ratio over a broad range of operating conditions. The system also maintains a balance between the pressure of the fuel stream and the pressure of the oxidant stream.