Abstract: A fuel supply system for a fuel cell is described. One embodiment of the fuel supply system includes a fuel supply vessel; a fuel spending line in fluid communication with the fuel supply vessel and the fuel cell; a piezoelectric injector in fluid communication with the fuel spending line; and a pressure sensor connected to the fuel spending line and positioned between the fuel supply vessel and the fuel cell. A method for controlling the pressure to a fuel cell is also described.

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 and system for preventing gas pressure in a pressure vessel from dropping below a minimum allowable pressure. Pressure readings from a pressure sensor downstream of a pressure regulator are monitored by a processor as they vary within a steady fluctuation band under normal regulated pressure conditions. When the pressure regulator reaches a fully open position in low vessel pressure conditions, the processor detects a drop in the pressure reading to a value below the recent fluctuation band, and recognizes that the pressure is dropping below the regulation pressure value. The processor can use this information to shut off flow of gas from the vessel, thus preventing the vessel from dropping below its minimum allowable pressure, regardless of the actual magnitude of the pressure reading from the sensor—which can vary through a wide range due to tolerances.

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 and system for automatically calibrating all pressure sensors in a hydrogen storage system for a fuel cell vehicle. A pressure regulator in the hydrogen storage system, which has much greater accuracy at low pressures, is used to calibrate the high-range pressure sensors used in the hydrogen storage system. This calibration can only be done when the pressure regulator is in a fully open position. In such a condition, the pressure sensors can be calibrated to the regulation pressure value of the regulator, thus greatly improving the accuracy of the readings of the high-range sensors at the low end of their range. The calibration can be performed during fuel cell operation under certain circumstances, performed during a programmed shutdown sequence, or performed in a service procedure.

Abstract: A fuel supply system for a fuel cell is described. One embodiment of the fuel supply system includes a fuel supply vessel; a fuel spending line in fluid communication with the fuel supply vessel and the fuel cell; a piezoelectric injector in fluid communication with the fuel spending line; and a pressure sensor connected to the fuel spending line and positioned between the fuel supply vessel and the fuel cell. A method for controlling the pressure to a fuel cell is also described.

Abstract: A method and system for automatically calibrating all pressure sensors in a hydrogen storage system for a fuel cell vehicle. A pressure regulator in the hydrogen storage system, which has much greater accuracy at low pressures, is used to calibrate the high-range pressure sensors used in the hydrogen storage system. This calibration can only be done when the pressure regulator is in a fully open position. In such a condition, the pressure sensors can be calibrated to the regulation pressure value of the regulator, thus greatly improving the accuracy of the readings of the high-range sensors at the low end of their range. The calibration can be performed during fuel cell operation under certain circumstances, performed during a programmed shutdown sequence, or performed in a service procedure.

Abstract: A method and system for preventing gas pressure in a pressure vessel from dropping below a minimum allowable pressure. Pressure readings from a pressure sensor downstream of a pressure regulator are monitored by a processor as they vary within a steady fluctuation band under normal regulated pressure conditions. When the pressure regulator reaches a fully open position in low vessel pressure conditions, the processor detects a drop in the pressure reading to a value below the recent fluctuation band, and recognizes that the pressure is dropping below the regulation pressure value. The processor can use this information to shut off flow of gas from the vessel, thus preventing the vessel from dropping below its minimum allowable pressure, regardless of the actual magnitude of the pressure reading from the sensor—which can vary through a wide range due to tolerances.