Abstract: The present invention concerns a system and a fuel ejector for controlling the fuel flow in proton exchange membrane fuel cells. The ejector comprises a nozzle receiving pressurized fuel from a first inlet into said ejector and including a first tapered section narrowing towards the outlet end of said nozzle in order to provide a flow of fuel, a second inlet for receiving recirculated fuel from a proton exchange membrane fuel cell, a diffuser comprising at least a second tapered section receiving fuel from said nozzle and said second inlet, and an outlet for delivering fuel from said diffuser to the anode system of said proton exchange membrane fuel cell. A shaped elongate rod having a butt end and an opposite pointed is movable lengthwise along its axis to engage with said first tapered section in order to provide a fuel flow control means for the fuel at the outlet of said nozzle.

Abstract: The invention relates to a method of determining water accumulation in and or removal from a fuel cell, the method comprising circulating fuel gas in the anode side of the fuel cell for producing electric energy in a fuel cell process, providing at least two purge pulses from the fuel circulation, analyzing the composition and/or volume of purged gas of said at least two gas purge pulses for determining the amount of water accumulation in and/or removal from the fuel cell.

Abstract: The invention relates to a system and a method for eliminating reverse current decay in the fuel cells. According to the invention, the system comprises a fuel cell having an anode and a cathode; a fuel feed system for supplying the anode of the fuel cell with fuel and forming an anode system; a bypass line fitted in parallel and in flow connection with said anode system and capable of circulating fuel past the anode; an oxygen reduction unit; and a pressure unit for circulating gas in at least part of said anode system and said bypass line. The bypass line is adapted to receive and circulate a flow of hydrogen during a fuel cell shutdown in order to mix the hydrogen with any oxygen present in the anode system, and to remove the oxygen from the anode system in said oxygen reduction unit by catalytic conversion.

Abstract: A flow field plate for a bipolar plate or bipolar plate assembly of a fuel cell or a fuel cell stack has an electrode facing front side, a backside and at least a cooling fluid manifold for supplying cooling fluid to the flow field plate. The backside includes a cooling fluid flow field for substantially uniformly distributing the cooling fluid over the flow field plate. The flow field plate further includes a cooling fluid sub-manifold which is adapted to provide cooling fluid from the cooling fluid manifold to a cooling fluid flow field. The cooling fluid sub-manifold is fluidly disconnected from the cooling fluid flow field, a bipolar plate or bipolar plate assembly including a flow field plate, as well as a fuel cell or fuel cell stack including such a flow field plate and/or bipolar plate or such a bipolar plate assembly.

Abstract: The invention relates to a system and a method for eliminating reverse current decay in the fuel cells. According to the invention, the system comprises a fuel cell having an anode and a cathode; a fuel feed system for supplying the anode of the fuel cell with fuel and forming an anode system; a bypass line fitted in parallel and in flow connection with said anode system and capable of circulating fuel past the anode; an oxygen reduction unit; and a pressure unit for circulating gas in at least part of said anode system and said bypass line. The bypass line is adapted to receive and circulate a flow of hydrogen during a fuel cell shutdown in order to mix the hydrogen with any oxygen present in the anode system, and to remove the oxygen from the anode system in said oxygen reduction unit by catalytic conversion.

Abstract: The invention relates to a method of determining water accumulation in and or removal from a fuel cell, the method comprising circulating fuel gas in the anode side of the fuel cell for producing electric energy in a fuel cell process, providing at least two purge pulses from the fuel circulation, analyzing the composition and/or volume of purged gas of said at least two gas purge pulses for determining the amount of water accumulation in and/or removal from the fuel cell.

Abstract: A polymer electrolyte fuel cell structure includes a proton exchange membrane (4). An anode catalyst layer (1,16) is located on one side of the proton exchange membrane. A cathode catalyst layer (7) is located on the opposite side of the proton exchange membrane, and a gas distribution layer (3,5) is arranged on each side of the proton exchange membrane (4). The anode side gas distribution layer (3) is a flat, porous structure having water channels (3a) formed in the surface facing the membrane (4). The anode side gas distribution layer (3) is enclosed by a coplanar, sealing plate (2) with water inlet channels coupled to the water channels (3a) in the gas distribution layer.

Abstract: A bipolar plate made of a composition comprising at least an epoxy resin, graphite filler and a metal amine complex as a curing agent for the epoxy resin. The invention also relates to a method for producing a bipolar plate and to the use of the bipolar plates in PEM fuel cells.

Abstract: A polymer electrolyte fuel cell structure includes a proton exchange membrane (4). An anode catalyst layer (1,16) is located on one side of the proton exchange membrane. A cathode catalyst layer (7) is located on the opposite side of the proton exchange membrane, and a gas distribution layer (3,5) is arranged on each side of the proton exchange membrane (4). The anode side gas distribution layer (3) is a flat, porous structure having water channels (3a) formed in the surface facing the membrane (4). The anode side gas distribution layer (3) is enclosed by a coplanar, sealing plate (2) with water inlet channels coupled to the water channels (3a) in the gas distribution layer.