Abstract: A method for cooling a fuel cell (3) using a liquid cooling medium, wherein of the starting materials supplied to the fuel cell and the products discharged from the fuel cell, at least one is gaseous during at least one of the operating conditions. The cooling medium is conveyed through the fuel cell (3) by a coolant conveying device (11). The power consumption of the coolant conveying device (11) is compared to predefined reference values in order to detect gas in the liquid cooling medium by a deviation of the power consumption from the predefined reference values.

Abstract: A functional module for a coolant circuit of a vehicle fuel cell system includes a container having an ion-exchange material and a pump device for the coolant fluidically coupled to each other in such a manner that a coolant inlet and a coolant outlet of the pump device are connected to a coolant outlet and a coolant inlet of the container. The container surrounds at least one region of the pump device that has a conveying unit of the pump device at least in certain areas around the outer circumference.

Abstract: A method for monitoring the functioning of an electric motor-driven pump (1), preferably in a vehicle (F), which has an internal electronics system (4) by means of which functional parameters of the pump (1) are monitored. The internal electronic system (4) relays the values of the functional parameters to a central control device (8) via an internal communication interface (6), and the values of the functional parameters are detected and monitored in the central control device (8) with respect to critical limiting values. The change over time of at least one value of the functional parameters is detected in the central control device (8), and a malfunction of the pump (1) is deduced if a value of at least one functional parameter remains constant over a predefined period of time.

Abstract: A method for cooling a fuel cell (3) using a liquid cooling medium, wherein of the starting materials supplied to the fuel cell and the products discharged from the fuel cell, at least one is gaseous during at least one of the operating conditions. The cooling medium is conveyed through the fuel cell (3) by a coolant conveying device (11). The power consumption of the coolant conveying device (11) is compared to predefined reference values in order to detect gas in the liquid cooling medium by a deviation of the power consumption from the predefined reference values.

Abstract: A fuel cell system which can be used in a mobile manner with a fuel cell unit (1) in order to produce electric energy, and an adsorption accumulator (3) which is associated with a fuel cell unit (1) are provided. The adsorption accumulator (3) is used to release heat and interacts in a thermal manner with a heat exchanger (2) which is arranged downstream from the fuel cell unit (1) in a cooling circuit (4, 5) associated with the fuel cell unit. A method for operating said type of fuel cell system, especially during a cold start is provided.

Abstract: A fuel cell system which can be used in a mobile manner with a fuel cell unit (1) in order to produce electric energy, and an adsorption accumulator (3) which is associated with a fuel cell unit (1) are provided. The adsorption accumulator (3) is used to release heat and interacts in a thermal manner with a heat exchanger (2) which is arranged downstream from the fuel cell unit (1) in a cooling circuit (4, 5) associated with the fuel cell unit. A method for operating said type of fuel cell system, especially during a cold start is provided.

Abstract: An embossed fluid flow field plate for electrochemical cells comprises two sheets of compressible, electrically conductive material. Each sheet has two oppositely facing major surfaces. At least one of the major surfaces has an embossed surface which has a fluid inlet formed therein. The embossed surface has at least one open-faced channel embossed therein extending from the fluid inlet for conducting pressurized fluid introduced at the fluid inlet. A metal sheet is interposed between each of the compressible sheets. The compressible, electrically conductive sheet preferably comprises graphite foil. A method of fabricating an embossed separator plate for use in conjunction with an electrochemical fuel cell comprises (1) providing two sheets of compressible, electrically conductive sheet material, (2) interposing a metal sheet between each of the compressible sheets, and (3) embossing an open-faced channel in at least one of the surfaces of the sheets facing away from the metal sheet.

Abstract: An embossed fluid flow field plate for electrochemical cells comprises two sheets of compressible, electrically conductive material. Each sheet has two oppositely facing major surfaces. At least one of the major surfaces has an embossed surface which has a fluid inlet formed therein. The embossed surface has at least one open-faced channel embossed therein extending from the fluid inlet for conducting pressurized fluid introduced at the fluid inlet. A metal sheet is interposed between each of the compressible sheets. The compressible, electrically conductive sheet preferably comprises graphite foil.