Abstract: An energy management system controls the temperature of a fuel cell system while a vehicle is not running. The energy management system includes a fuel cell stack, a blower that provides air to the fuel cell stack, a water supply, and a hydrogen supply. A hydrogen supply valve is connected between the hydrogen supply and the fuel cell stack. A heater is connected to an output of the fuel cell stack. A controller controls the hydrogen supply valve and the blower to power the heater to warm the fuel cell stack and the water supply. The controller starts the blower and opens the hydrogen supply valve if heating is necessary and if a tank level signal exceeds a first tank level value. The controller activates a purge, drains water from the water supply, and inhibits vehicle startup if the tank level signal does not exceed a first tank level value.

Abstract: The present invention discloses a fuel cell system that reduces a hydrogen content of anode effluent exhausted by a fuel cell stack without the use of a tail gas combustor. The fuel cell system reduces the hydrogen content in one or more stages to a level suitable for venting to the environment. A first stage reduction is provided by mixing a portion of the cathode effluent with a controlled quantity of the anode effluent in the presence of a catalytic bed. The resulting stream has a reduced hydrogen content which can then be supplied to the cathode inlet side of the fuel cell stack for further hydrogen content reduction. The fuel cell system also provides a storage device to store the anode effluent to minimize pressure fluctuations between the anode and cathode sides of the fuel cell stack during a purging operation.

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: 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.

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.

Abstract: An energy management system controls the temperature of a fuel cell system while a vehicle is not running. The energy management system includes a fuel cell stack, a blower that provides air to the fuel cell stack, a water supply, and a hydrogen supply. A hydrogen supply valve is connected between the hydrogen supply and the fuel cell stack. A heater is connected to an output of the fuel cell stack. A controller controls the hydrogen supply valve and the blower to power the heater to warm the fuel cell stack and the water supply. The controller starts the blower and opens the hydrogen supply valve if heating is necessary and if a tank level signal exceeds a first tank level value. The controller activates a purge, drains water from the water supply, and inhibits vehicle startup if the tank level signal does not exceed a first tank level value.

Abstract: The present invention discloses a fuel cell system that reduces a hydrogen content of anode effluent exhausted by a fuel cell stack without the use of a tail gas combustor. The fuel cell system reduces the hydrogen content in one or more stages to a level suitable for venting to the environment. A first stage reduction is provided by mixing a portion of the cathode effluent with a controlled quantity of the anode effluent in the presence of a catalytic bed. The resulting stream has a reduced hydrogen content which can then be supplied to the cathode inlet side of the fuel cell stack for further hydrogen content reduction. The fuel cell system also provides a storage device to store the anode effluent to minimize pressure fluctuations between the anode and cathode sides of the fuel cell stack during a purging operation.

Abstract: An energy management system controls the temperature of a fuel cell system while a vehicle is not running. The energy management system includes a fuel cell stack, a blower that provides air to the fuel cell stack, a water supply, and a hydrogen supply. A hydrogen supply valve is connected between the hydrogen supply and the fuel cell stack. A heater is connected to an output of the fuel cell stack. A controller controls the hydrogen supply valve and the blower to power the heater to warm the fuel cell stack and the water supply. The controller starts the blower and opens the hydrogen supply valve if heating is necessary and if a tank level signal exceeds a first tank level value. The controller activates a purge, drains water from the water supply, and inhibits vehicle startup if the tank level signal does not exceed a first tank level value.

Abstract: An energy management system controls the temperature of a fuel cell system while a vehicle is not running. The energy management system includes a fuel cell stack, a blower that provides air to the fuel cell stack, a water supply, and a hydrogen supply. A hydrogen supply valve is connected between the hydrogen supply and the fuel cell stack. A heater is connected to an output of the fuel cell stack. A controller controls the hydrogen supply valve and the blower to power the heater to warm the fuel cell stack and the water supply. The controller starts the blower and opens the hydrogen supply valve if heating is necessary and if a tank level signal exceeds a first tank level value. The controller activates a purge, drains water from the water supply, and inhibits vehicle startup if the tank level signal does not exceed a first tank level value.

Abstract: Method for controlling the supply of air to a PROX reactor for the preferential oxidation in the presence of hydrogen wherein the concentration of the hydrogen entering and exiting the PROX reactor is monitored, the difference therebetween correlated to the amount of air needed to minimize such difference, and based thereon the air supply to the PROX reactor adjusted to provide such amount and minimize such difference.