Patent ID: 8158291
Filing Date: 2012-04-17
Classification: F01D,H01M,Y02B,Y02E

Abstract:
1. A system for recirculating an unused hydrogen stream to a fuel cell stack, the system comprising: a fuel supply adapted to provide a pressurized supply hydrogen stream; an expander in fluid communication with the fuel supply and configured to receive the pressurized supply hydrogen stream, to reduce pressure of the pressurized supply hydrogen stream, to produce a reduced pressure hydrogen stream, and to generate mechanical energy in response to reducing the pressure of the pressurized supply hydrogen stream; an electric machine operably coupled to the expander and for selectively converting the mechanical energy generated by the expander into electrical energy; a compressor/blower capable of being driven by at least one of the mechanical energy and the electrical energy to control the flow of the unused hydrogen stream; at least one flow-combining device in fluid communication with the expander and the compressor/blower for combining the unused hydrogen stream with the reduced pressure supply hydrogen stream to produce an input hydrogen stream; and the fuel cell stack being in fluid communication with the flow-combining device and the compressor/blower to receive the input hydrogen stream from the flow-combining device and an air stream, to generate electrical power for a vehicle in response to the air stream and the input hydrogen stream, and to provide the unused hydrogen stream to the compressor/blower.