Abstract: A method of removing moisture from a fuel cell stack. The presence of liquid water in a fuel cell stack is especially undesirable should the temperature drop below freezing since the structures within the fuel cell are subject to degradation. One method includes measuring the temperature in the vicinity of a fuel cell vehicle when the fuel cell vehicle has been shut down and measuring the time elapsed since fuel cell vehicle shut off, and then flowing a moisture-removing medium through the fuel cell when the ambient temperature drops to a predetermined temperature and a time delay condition is satisfied. The moisture-removing medium is flowed through the fuel cell for a sufficient time to remove a sufficient amount of the water to inhibit degradation by freezing of water. A system which implements the method of the present invention is also provided.

Abstract: A method of removing moisture from a fuel cell stack is provided. The presence of liquid water in a fuel cell stack is undesirable should the temperature drop below freezing since the structures within the fuel cell are subject to degradation and potentially damage by ice formation. The method of the invention comprises measuring the temperature in the vicinity of a fuel cell vehicle when the fuel cell vehicle has been shut down, and then flowing a moisture-removing medium through the fuel cell when the ambient temperature drops to a predetermined temperature. The moisture-removing medium is flowed through the fuel cell for a sufficient time to remove a sufficient amount of the water in the fuel cell so that the fuel cell is not degraded by freezing of water. The present invention also provides a fuel cell water removing system which implements the method of the present invention.

Abstract: A fuel cell system having an air source to dilute hydrogen emissions upon shutdown of the system is disclosed. The air reservoir includes a fuel cell stack module and a hydrogen source, a main air source and an auxiliary air source provided in fluid communication with the fuel cell stack module for diluting hydrogen emissions from the fuel cell stack module upon shutdown of the fuel cell system. A method of diluting hydrogen emissions from a fuel cell system is also disclosed.

Abstract: A sensor for measuring and controlling pressure, temperature and relative humidity of a gas process stream for a powerplant is disclosed. Sensor elements are integrated to form a compact module at a single location in the stream.

Abstract: A method of removing moisture from a fuel cell stack. The presence of liquid water in a fuel cell stack is especially undesirable should the temperature drop below freezing since the structures within the fuel cell are subject to degradation. One method includes measuring the temperature in the vicinity of a fuel cell vehicle when the fuel cell vehicle has been shut down and measuring the time elapsed since fuel cell vehicle shut off, and then flowing a moisture-removing medium through the fuel cell when the ambient temperature drops to a predetermined temperature and a time delay condition is satisfied. The moisture-removing medium is flowed through the fuel cell for a sufficient time to remove a sufficient amount of the water to inhibit degradation by freezing of water. A system which implements the method of the present invention is also provided.

Abstract: A method of removing moisture from a fuel cell stack is provided. The presence of liquid water in a fuel cell stack is undesirable should the temperature drop below freezing since the structures within the fuel cell are subject to degradation and potentially damage by ice formation. The method of the invention comprises measuring the temperature in the vicinity of a fuel cell vehicle when the fuel cell vehicle has been shut down, and then flowing a moisture-removing medium through the fuel cell when the ambient temperature drops to a predetermined temperature. The moisture-removing medium is flowed through the fuel cell for a sufficient time to remove a sufficient amount of the water in the fuel cell so that the fuel cell is not degraded by freezing of water. The present invention also provides a fuel cell water removing system which implements the method of the present invention.

Abstract: The voltage of each of a plurality of energy providing cells such, as battery or fuel cells, is measured using simple analog components. A comparator circuit connected to each cell compares the cell voltage with a varying reference voltage produced by a voltage ramp generator, and produces a digital output signal when the cell voltage is in a prescribed relationship to the reference voltage. A monitoring circuit receives the digital signals from the comparators and determines the cell voltage based on the value of the reference voltage at the point in time when the digital signal in generated.