Abstract:
The focus of the invention is an arrangement for minimizing need for safety gases in high temperature fuel cell system, each fuel cell in the fuel cell system comprises an anode side (100), a cathode side (102), and an electrolyte (104) between the anode side and the cathode side, the fuel cells being arranged in fuel cell stacks (103), and the fuel cell system comprises a fuel cell system piping for reactants, and means (108) for feeding fuel to the anode sides (100) of the fuel cells. The arrangement comprises means (122) for electrical anode protection supplying a predefined voltage separately to at least two fuel cell stacks (103) or groups of fuel cell stacks (103) to prohibit oxidation of anodes (100), a source (120) of energy sufficient for providing electrical energy for at least a predetermined minimum time for said means (122) for electrical anode protection, means (124) to reduce said predefined voltage to limit anode protection current to a predefined maximum current value separately for at least two stacks (103) or groups of stacks (103), and means (126) to reliably trigger said means (122) for electrical anode protection in a situation where anode oxidation cannot be prohibited by the means (108) for feeding fuel to the anode sides (100) of the fuel cells.
Abstract:
L'invention concerne un procédé de protection contre la corrosion d'un ensemble de cellules électrochimiques (C1,C2,C3) incluses dans une pile à combustible durant une phase d'extinction de la pile, comprenant les étapes de: -mesurer la tension aux bornes de chacune des cellules à protéger; -lorsque la tension mesurée pour une cellule est supérieure à un seuil de protection, décharger (50) cette cellule dans une charge électrique (R1,R2,R3); -lorsque la tension mesurée pour une cellule est inférieure audit seuil de protection, découpler cette cellule de la charge électrique.
Abstract:
The present invention provides a gas generator that may be used for startup and shutdown of a fuel cell. In one non-limiting embodiment, the gas generator may include a nitrogen generator structured to receive air, extract oxygen (O 2 ) from the air and discharge the balance in the form of a nitrogen-rich gas; a merging chamber structured to receive a hydrocarbon fuel and the nitrogen-rich gas and to discharge a feed mixture containing both the hydrocarbon fuel and the nitrogen-rich gas; and a catalytic reactor structured to receive the feed mixture and to catalytically convert the feed mixture into a reducing gas.
Abstract:
A method for removing contaminants in a fuel cell comprises: supplying a hydrogen-based fuel to the anode; supplying a first oxidant to the cathode, wherein the first oxidant comprises at least some sulfur dioxide; drawing a primary load from the fuel cell stack while supplying the hydrogen-based fuel to the anode and the air to the cathode; shutting down the fuel cell when a voltage of the fuel cell is equal to or less than a threshold voltage at which sulfur crosses over from the cathode to the anode, wherein shutting down the fuel cell comprises: performing at least one oxidant starvation while drawing the primary load, removing the primary load after performing the at least one oxidant starvation, and bringing the anode to a high potential after removing the primary load; and thereafter, restarting the fuel cell.
Abstract:
Die Erfindung betrifft ein Verfahren zum Betreiben eines Brennstoffzellensystems (1) mit wenigstens einer Brennstoffzelle (2) und wenigstens einer Anodenrezirkulationseinrichtung mit zumindest einer Rezirkulationsfördereinrichtung (7) und einem Ablassventil (8). Während einer nach dem Abstellen des Brennstoffzellensystems (1) startenden Abschaltprozedur wird die Rezirkulationsfördereinrichtung (7) zumindest zeitweise bei geöffnetem Ablassventil (8) weiter betrieben. Erfindungsgemäß ist dabei im Bereich der Rezirkulationsfördereinrichtung (7) eine Wärmequelle (9) vorgesehen, durch welche während der Abschaltprozedur und/oder während eines Systemstarts des Brennstoffzellensystems (1) zumindest zeitweise eine Beheizung erfolgt.
Abstract:
To mitigate corrosion of carbon in and around the catalysts of a fuel cell power plant (5), the gases in the anodes (6) and/or cathodes (10) are homogenized when the fuel cell plant is not in operation, by operating either or both of the anode gas recycle function (19-23) or the cathode gas recycle function (34, 35, 42, 44-47), either continuously, and/or intermittently (126, 128), and/or immediately (131-138) before start up of the fuel cell power plant.