Siemens Aktiengesellschaft

Igor Mehltretter

Arno Mattejat

Albert Hammerschmidt

Josef Lersch

Herbert Hartnack

Ottmar Voitlein

Walter Stühler

Dieter Illner

Johann Rothfischer

Torsten Lochner

A fuel cell with a gas chamber, arranged between two plate elements, is provided. One of the plate elements includes bosses for supporting the plate element on the other plate element in a regular grid structure. Between the bosses runs a network of gas channels passing through the gas chamber, the bosses being at most three times longer than wide. The bosses form between themselves first gas channels in a first region of the gas chamber and larger-volume second gas channels in a second region of the gas chamber.

Fuel cell

The invention relates to a contact device which is arranged in a terminal compartment of a fuel cell stack and is used to electrically contact the fuel cell stack. According to the invention, the surface of said contact device is at least partially provided with a hydrophobic surface layer, facilitating the removal of water, e.g., condensation water, from the terminal compartment and thus from the fuel cell stack.

Contact device and fuel cell stack or fuel cell block comprising one such contact device

When an insulator is used in a humid atmosphere, the cooling thereof causes a humidity condensation, which is deposited on the insulator surface. Drops of water formed by the humidity condensation are connected to each other that a water film substantially reducing the insulation resistance of the insulator is formed. In order to solve said problem, the inventive insulator is provided, at least partially, with a hydrophobe surface. In such a way, the water layers formed by condensation are drained off the surface or detached there from without connection and the drops of water produced by condensation are unable to be bound to each other, thereby making it possible to maintain a desired high insulation resistance.

Insulator with enhanced insulating capacity

A defective operation of a valve () in a drainage line () of a fuel cell results in unintentionally permitting process gas to flow into the surrounding area of the fuel cells. In order to resolve this problem, the invention provides a method for monitoring the discharge of media out of a fuel cell and provides a fuel cell system, with which the gas and water stream flowing through the drainage line () is monitored () by means of a Venturi nozzle () that is connected to a differential pressure sensor (). The magnitude () and the temporal progression () of the differential pressure indicated by the differential pressure sensor () establishes the basis for controlling the valve () in the drainage line () and for shutting down () the fuel cell block () in the event that the valve () is defective.

Method for monitoring the discharge of media out of fuel cell, and a fuel cell system

A fuel cell module includes a number of series-connected fuel cells forming a fuel cell stack. To reliably ensure that there is no risk of the fuel cell stack buckling, even where a comparatively large number of fuel cells are grouped to form a fuel cell stack, the fuel cell stack is surrounded by a stabilizing casing, at least in a middle area as seen in the longitudinal direction.

Growing community of inventors

Buckenhof, Germany

Igor Mehltretter