Abstract: A fluid delivery device for an electrochemical conversion assembly. In one embodiment, the electrochemical conversion assembly is a fuel cell system. The device includes one or more fluid-manipulating components combined into a housing to minimize weight, size and complexity. In one form, the device may include a compressor, heat exchanger and a water vapor transfer unit, at least the latter two of which are located within a chamber defined by the housing. A controller can be used to monitor and selectively vary the extent to which at least one of these components modifies properties a fluid (such as air) that can be used as a reactant in the electrochemical conversion assembly. In a particular form, the heat exchanger and water vapor transfer unit can cooperate to promote the hydration of the reactant.

Abstract: A fuel cell system that uses compressed and heated cathode input air to heat the fuel cell stack at system start-up. The system includes a heat exchanger that uses the system cooling fluid to cool the compressed and heated cathode input air before it is sent to the fuel cell stack. At system start-up, a proportional by-pass valve directs a controlled portion of the cooling fluid around the heat exchanger so that the heated cathode input air can be used to heat the fuel cell stack. Once the stack reaches its operating temperature, the by-pass valve does not by-pass the heat exchanger. The fuel cell system also includes an inlet air valve that is used to choke the compressor at system start-up to cause the compressor to rapidly heat the compressed air.

Abstract: An apparatus and method to produce hydrogen gas a high pressure is disclosed. An electrolyzer is located inside a pressure vessel that is pressurized with high pressure water. The high pressure water is provided to both the anode and cathode sides of the electrolyzer by a pump in the pressure vessel Oxygen produced at the high pressure on the anode side of the electrolyzer is vented directly into the pressure vessel while hydrogen produced at the high pressure on the cathode side is routed to a separator and is deadheaded. The high pressure hydrogen is periodically routed from the separator to a storage tank by a pressure regulator.