Abstract: A method of reducing freeze-thaw delamination of electrode layers from the electrolyte membranes in a fuel cell is disclosed. The method comprises reducing the water content of the MEA to or below 80 percent of saturation prior to exposing the MEA to freezing conditions. Most preferably the water content of the MEA is reduced to or below about 40 percent of saturation.

Abstract: A method of fuel cell shutdown and start-up is provided. The method of shutdown includes introducing hydrogen gas into the cathode passages to purge a cathode gas from the cathode passages, then introducing air through the cathode and anode passages to remove water droplets and vapor from the fuel cell stacks. The method from fuel cell start-up includes introducing hydrogen gas into the anode and cathode passages to consume/purge oxygen in both the anode and cathode passages, and then introducing a cathode gas into the cathode passages. The introduction of hydrogen into the cathode passages in both the shutdown and start-up procedures allow a rapid draw down of the anode/cathode open circuit voltage and avoids providing a hydrogen/air front while the cathode is filled with air.

Abstract: A fuel cell system that employs a procedure for delaying an air purge of a fuel cell stack at system shut-down until the temperature of the stack is reduced below a predetermined temperature. The fuel cell stack includes an anode side, a cathode side, an anode input, a cathode input and an anode exhaust. The system includes a temperature sensor for monitoring the temperature of a cooling fluid flowing through the stack. The anode side of the fuel cell stack is purged at the stack shut-down by directing air from the cathode input line to the anode input line after the temperature of the cooling fluid is reduced to a predetermined temperature.

Abstract: A method and apparatus for spin forming a portion of a workpiece where the formed portion has a formed axis that is non-coaxial with the non-processed axis of the workpiece includes at least two rollers rotatable about a spin axis. Each one of the rollers is axially and radially offset from the others. An axial drive mechanism reciprocates the rollers or workpiece to causes the first roller and then the second roller to sequentially engage the workpiece. A pivoting mechanism rotates the rollers or workpiece about a pivot point from a first angular position to a second angular position during a forming operation to create a formed portion that is oblique to the non-processed portion or is substantially curved. A higher reduction ratio is achieved which enables improved efficiency. The present invention reduces floor space requirements as the forming operation may be completed on a single machine.

Abstract: A method and apparatus for spin forming a portion of a workpiece includes at least two rollers rotatable about a spin axis. Each one of the rollers is axially and radially offset from the others. An axial drive mechanism reciprocates the rollers or workpiece to causes the first roller and then the second roller to sequentially engage the workpiece. A higher reduction ratio is achieved which enables improved efficiency. The present invention reduces floor space requirements as the forming operation may be completed on a single machine.

Abstract: The present invention provides for a method and apparatus for hydrogen detection and dilution. The present invention uses an enclosure within which a variety of components of a fuel cell system are located and a ventilation stream to vent the enclosure which is induced by operation of a compressor that also is operable to supply the oxygen to the fuel cell system. The ventilation stream is directed through an outlet in the enclosure that contains a hydrogen sensor that is operable to both detect the presence of hydrogen and to consume hydrogen within the ventilation stream prior to being exhausted from the enclosure. The ventilation stream, alternatively, can be induced by operation of a fan driven by a motor which operates independently of the operation of the oxidant delivery system.