Abstract: A fuel cell stack has a multiplicity of individual cells, which each include an anode flow field, a membrane electrode arrangement, and a cathode flow field. Each flow field has a media inlet and channels for carrying the media. The anode flow fields and/or the cathode flow fields have the media inlet on their upward-facing side when used as intended, and are open on their downward-facing side when used as intended.

Abstract: A fuel cell stack has a multiplicity of individual cells, which each include an anode flow field, a membrane electrode arrangement, and a cathode flow field. Each flow field has a media inlet and channels for carrying the media. The anode flow fields and/or the cathode flow fields have the media inlet on their upward-facing side when used as intended, and are open on their downward-facing side when used as intended.

Abstract: A method for operating a fuel cell system involves operating the fuel cell with recirculation of anode exhaust gas below a predefined maximum load limit of the fuel cell and operating the fuel cell without recirculation of the anode exhaust gas between the load limit and the full load of the fuel cell.

Abstract: A fuel cell system includes at least one fuel cell, line elements for supplying and discharging starting materials and/or products to/from the fuel cell, and at least one condensation unit. The condensation unit is situated in at least one of the line elements and, at least in individual operating phases of the fuel cell, the condensation unit is at a lower temperature level than the areas surrounding it and the fuel cell.

Abstract: A fuel supply system for a fuel cell stack includes a cathode gas supply line for supplying an oxidant to the cathode input of the fuel cell stack and an anode gas supply line for supplying fuel to the anode input of the fuel cell stack. An anode gas recirculation line recirculates partially used anode gas from the anode output to the anode input while a purge line may be connected for conducting away the partially used anode gas, as a purge gas from the anode gas recirculation line into the cathode gas supply line. The supply system also includes a conditioning arrangement disposed upstream of the cathode input. The conditioning arrangement is designed to a) mix a partial flow of the oxidant with the purge gas in a mixing station, b) compress accelerate, and/or heat the partial flow or the mixed flow, and c) conduct the mixed flow into the cathode gas supply line.

Abstract: A seal arrangement in a fuel cell device seals against leaks in a mechanical joint between two components which convey a liquid and/or a gaseous process medium 3 in a media chamber of the fuel cell device. The seal arrangement has a first sealing member which extends around the media chamber in an installed state, and is in active connection with the components. A second, surrounding sealing member is arranged facing away from the media relative to the first sealing member and is formed of a different material from the first sealing member and/or has a different geometry.

Abstract: An apparatus for supplying a fuel cell in a fuel cell system with fuel gas is provided. The fuel cell system includes a mixing region, where unused fuel gas mixes with fresh fuel gas, a water precipitator, a device for the at least indirect heating of the supplied fresh fuel gas and at least one receptor for a sensor for sensing state variables and/or chemical magnitudes of the fuel gas flowing to the anode. The mixing region, water precipitator, device for the at least indirect heating and at least one sensor are combined in an integrated component part.

Abstract: The object of the invention is to improve the sealing properties of a seal arrangement in a fuel cell device for sealing against leaks a mechanical joint between two components of the fuel cell device. The invention proposes a seal arrangement in a fuel cell device for sealing against leakage a mechanical joint between two components I1, 1? of the fuel cell device, which components convey a liquid and/or a gaseous process medium 3 in a media chamber 2, the seal arrangement having a scaling member 9, 12 which is constructed to extend around the media chamber 2 and which is in active connection with the components 1?, 1?. The object is achieved in that a second, surrounding sealing member 10, 13 is provided, which is arranged facing away from the media relative to the first sealing member 9, 12 and is of a different material from the first sealing member 9, 12 and/or has a different geometry.

Abstract: A fuel supply system for a fuel cell stack includes a cathode gas supply line for supplying an oxidant to the cathode input of the fuel cell stack and an anode gas supply line for supplying fuel to the anode input of the fuel cell stack. An anode gas recirculation line recirculates partially used anode gas from the anode output to the anode input while a purge line may be connected for conducting away the partially used anode gas, as a purge gas from the anode gas recirculation line into the cathode gas supply line. The supply system also includes a conditioning arrangement disposed upstream of the cathode input. The conditioning arrangement is designed to a) mix a partial flow of the oxidant with the purge gas in a mixing station, b) compress accelerate, and/or heat the partial flow or the mixed flow, and c) conduct the mixed flow into the cathode gas supply line.