Abstract: High pressure gas vessels can have a sensitivity to temperature of the compressed gas. Over-temperature conditions in particular may cause decreased durability and/or vessel damage, including gas leakage to the environment. Articles of manufacture, methods, and systems are provided for over-temperature protection using a passive device. The passive closing device does not require electrical power and no controller, sensors, or wiring is needed. This affords cost savings in comparison to other systems. Pressure vessels using the passive closing device can protect themselves, independent of the compressed gas fueling station configuration.

Abstract: A drainage device for placement on a housing includes an external plug component and a liquid expandable component. The external plug component has a first cap section and a second attachment section. The first cap section is positionable over an exterior side of a housing wall. The first attachment section is adapted to attach the drainage device to an opening in the housing wall. The liquid expandable component contacts the external plug component and is adapted to contact a structure within the housing when the drainage device is placed on the housing. Characteristically, the liquid expandable component has a higher volume when contacted with liquid than when dry. The liquid expandable component pushes the internal plug component away from the structure within the housing when the liquid expandable component transitions from a non-liquid-containing state to a liquid containing state thereby providing a path for liquid to escape.

Abstract: A drainage device for placement on a housing includes an external plug component and a liquid expandable component. The external plug component has a first cap section and a second attachment section. The first cap section is positionable over an exterior side of a housing wall. The first attachment section is adapted to attach the drainage device to an opening in the housing wall. The liquid expandable component contacts the external plug component and is adapted to contact a structure within the housing when the drainage device is placed on the housing. Characteristically, the liquid expandable component has a higher volume when contacted with liquid than when dry. The liquid expandable component pushes the internal plug component away from the structure within the housing when the liquid expandable component transitions from a non-liquid-containing state to a liquid containing state thereby providing a path for liquid to escape.

Abstract: High pressure gas vessels can have a sensitivity to temperature of the compressed gas. Over-temperature conditions in particular may cause decreased durability and/or vessel damage, including gas leakage to the environment. Articles of manufacture, methods, and systems are provided for over-temperature protection using a passive device. The passive closing device does not require electrical power and no controller, sensors, or wiring is needed. This affords cost savings in comparison to other systems. Pressure vessels using the passive closing device can protect themselves, independent of the compressed gas fueling station configuration.

Abstract: High pressure gas vessels can have a sensitivity to temperature of the compressed gas. Over-temperature conditions in particular may cause decreased durability and/or vessel damage, including gas leakage to the environment. Articles of manufacture, methods, and systems are provided for over-temperature protection using a passive device. The passive closing device does not require electrical power and no controller, sensors, or wiring is needed. This affords cost savings in comparison to other systems. Pressure vessels using the passive closing device can protect themselves, independent of the compressed gas fueling station configuration.

Abstract: A method of fueling with compressed gas is described. In one embodiment, the method includes providing a supply of compressed gas; providing a storage tank with a fueling line, and a nozzle in the fueling line, the nozzle movable between at least a flow reduction position and a full fuel flow position; initiating fueling from the supply of compressed gas with the nozzle in the flow reduction position for a predetermined time or until a minimum pressure is obtained; when the predetermined time or the minimum pressure is obtained, moving the nozzle to the full fuel flow position; and fueling the storage tank from the supply of compressed gas with the nozzle in the full fuel flow position until fueling is completed. A vehicle incorporating the nozzle is also disclosed.

Abstract: High pressure gas vessels can have a sensitivity to temperature of the compressed gas. Over-temperature conditions in particular may cause decreased durability and/or vessel damage, including gas leakage to the environment. Articles of manufacture, methods, and systems are provided for over-temperature protection using a passive device. The passive closing device does not require electrical power and no controller, sensors, or wiring is needed. This affords cost savings in comparison to other systems. Pressure vessels using the passive closing device can protect themselves, independent of the compressed gas fueling station configuration.

Abstract: A pressure retention valve with integrated valve is disclosed. The pressure retention valve with integrated valve includes a housing; an outer piston positioned in the housing; a main seal between the outer piston and the housing; an inner piston positioned in the outer piston, the inner piston having a bore containing a valve; a spring between the housing and a top of the outer piston; an ambient bore in the housing above the main seal; an outlet in the housing below the main seal; and a vessel connection in the housing adjacent to the bore of the inner piston. Methods of supplying fuel to a gas consuming system using the pressure retention valve are also described.

Abstract: One embodiment of the invention includes a product comprising a fuel cell stack comprising at least one coolant header, and at least one heater at least partially disposed in the at least one coolant header.

Abstract: A pressure retention valve with integrated valve is disclosed. The pressure retention valve with integrated valve includes a housing; an outer piston positioned in the housing; a main seal between the outer piston and the housing; an inner piston positioned in the outer piston, the inner piston having a bore containing a valve; a spring between the housing and a top of the outer piston; an ambient bore in the housing above the main seal; an outlet in the housing below the main seal; and a vessel connection in the housing adjacent to the bore of the inner piston. Methods of supplying fuel to a gas consuming system using the pressure retention valve are also described.

Abstract: A method of fueling with compressed gas is described. In one embodiment, the method includes providing a supply of compressed gas; providing a storage tank with a fueling line, and a nozzle in the fueling line, the nozzle movable between at least a flow reduction position and a full fuel flow position; initiating fueling from the supply of compressed gas with the nozzle in the flow reduction position for a predetermined time or until a minimum pressure is obtained; when the predetermined time or the minimum pressure is obtained, moving the nozzle to the full fuel flow position; and fueling the storage tank from the supply of compressed gas with the nozzle in the full fuel flow position until fueling is completed. A vehicle incorporating the nozzle is also disclosed.

Abstract: A system and method for operating a cooling fluid pump and cooling fluid heater in a vehicle when the vehicle is not being used so that the temperature of the cooling fluid does not drop to low in a cold environment. The system includes an AC connector for plugging the system into an AC power outlet. The system also includes AC/DC converter that converts the AC power to a DC signal suitable to operate the pump. The system also includes a temperature switch that closes if the ambient temperature falls below a predetermined temperature, which electrically connects the AC connector to the AC/DC converter. When the AC/DC converter is powered, a switch is closed to connect the pump to a pulse width modulation (PWM) generator to operate the pump. Further, when the temperature switch is closed, power is provided to the heater.

Abstract: A system and method for drying a fuel cell stack after stack shutdown. In one embodiment, a cooling fluid is pumped through the fuel cell stack after the system is shutdown to use the heat still available in the cooling fluid immediately after shutdown to provide thermal equilibrium in the stack. In another embodiment, the heated cooling fluid still available immediately after system shutdown is sent through a cathode input gas heat exchanger so that drying air from the system compressor is heated by the cooling fluid before it enters the stack. In another embodiment, a separate heat exchanger is provided that receives the drying gas prior to it being sent into the fuel cell stack.

Abstract: A diagnostic method of detecting component failures in a fuel cell anode subsystem involves estimating fuel flow through injectors and comparing the estimated flow with a model based upon the system parameters. An observer based model is used to determine a residual value, the difference between the hydrogen input and the hydrogen consumed, and the residual is compared with a threshold range. In alternative embodiments, the stack current and the state of the valves are used to calculate the required hydrogen flow through the injectors and the duty cycle of an injector is compared to a tolerance range.

Abstract: One embodiment of the invention includes a product comprising a fuel cell stack comprising at least one coolant header, and at least one heater at least partially disposed in the at least one coolant header.

Abstract: A method for opening tank shut-off valves in a fuel cell system that includes multiple pressurized tanks. A flow control device is positioned in a supply line downstream of the tank shut-off valves. When the system is started up, only one of the tank shut-off valves is opened to allow the pressure in the supply line to increase between the tank shut-off valves and the flow control device before the other tank shut-off valves are opened. Therefore, only one of the tank shut-off valves is subjected to the high pressure difference that induces significant valve wear and tear. The valve opening sequence is controlled so each of the tank shut-off valves is selected as the one to be opened at system start-up by a cycling process.

Abstract: A system and method for operating a cooling fluid pump and cooling fluid heater in a vehicle when the vehicle is not being used so that the temperature of the cooling fluid does not drop to low in a cold environment. The system includes an AC connector for plugging the system into an AC power outlet. The system also includes AC/DC converter that converts the AC power to a DC signal suitable to operate the pump. The system also includes a temperature switch that closes if the ambient temperature falls below a predetermined temperature, which electrically connects the AC connector to the AC/DC converter. When the AC/DC converter is powered, a switch is closed to connect the pump to a pulse width modulation (PWM) generator to operate the pump. Further, when the temperature switch is closed, power is provided to the heater.

Abstract: A heating system for a pipe or hose in a fuel cell system that include heaters and conductors to prevent water in the pipe or hose from freezing. A heater wire is provided in contact with the pipe, and a conductor is wrapped around the heater wire and the pipe, and a protective layer is wrapped around the conductor, where the conductor provides thermal isolation. For a plastic or rubber hose, an inner conductor is wrapped around the house and an outer conductor is wrapped around the inner conductor. Heater wire is positioned between the inner conductor and the outer conductor. A protective layer is then wrapped around the outer conductor.

Abstract: A method for opening tank shut-off valves in a fuel cell system that includes multiple pressurized tanks. A flow control device is positioned in a supply line downstream of the tank shut-off valves. When the system is started up, only one of the tank shut-off valves is opened to allow the pressure in the supply line to increase between the tank shut-off valves and the flow control device before the other tank shut-off valves are opened. Therefore, only one of the tank shut-off valves is subjected to the high pressure difference that induces significant valve wear and tear. The valve opening sequence is controlled so each of the tank shut-off valves is selected as the one to be opened at system start-up by a cycling process.

Abstract: A method for detecting leaks in a fuel cell system that includes a hydrogen storage tank, a primary shut-off valve and a secondary shut-off valve in a supply line. At shut-down, the primary shut-off valve is closed and the stack is temporarily left operating. The pressure is measured in the supply line between the valves. When the measured pressure has reached a predetermined shut-down pressure, the secondary shut-off valve is closed. At the next system start-up, the pressure is measured before the shut-off valves are opened, and the measured pressure is compared with the stored pressure. If the current pressure measurement is lower than the stored pressure measurement, it is an indication that the supply line between the shut-off valves or the secondary valve leaks. If the measured pressure is higher than the stored pressure, it is an indication that the primary valve leaks.