Abstract: A method of operating a PEM fuel cell including an anode feed circuit and a cathode feed circuit for feeding of an anode side with a reactant gas and for feeding a cathode side with a cathode gas. A shut-down mode for shutting down an electricity generating operation of the fuel system includes decreasing the supply of reactant gas and cathode gas in response of a shut-down signal, monitoring an output voltage of at least one cell of a fuel cell stack, monitoring the reactant gas pressure and the cathode gas pressure, electrically shunting of the at least one fuel cell in response of the output voltage reaching a predefined voltage level, at least reducing the pressure of the anode side to a predefined pressure level by means of at least one pump, and filling and/or flushing of at least the anode side with an inert gas.

Abstract: The present invention relates to a housing assembly for at least two fuel cells, comprising: a hollow profile-like body (12) extending in an axial direction (z) and being adapted to laterally encompass at least two fuel cells stacked on one another in axial direction (z), and a fastening mechanism to interconnect the body (12) with at least one end plate (18, 28) adapted to support the at least two fuel cells.

Abstract: A fuel cell system including: a fuel cell stack including plural fuel cells sandwiched between two end plates; a fuel supply system supplying a stream of fuel gas to the fuel cell stack; an oxidizer supply system supplying a stream of oxidizer gas to the fuel cell stack; a closed loop coolant circulation system driving a cooling liquid through the fuel cell stack so that the cooling liquid enters the fuel cell stack, absorbs heat from the fuel cells, and exits the fuel cell stack. The coolant circulation system includes a circulation pump driving the cooling liquid, a heat exchanger removing heat from the cooling liquid and for at least partially transferring the heat to the stream of fuel gas and/or the stream of oxidizer gas.

Abstract: The fuel cell system includes: at least one fuel cell adapted to generate electrical energy from a fuel gas and an oxidizer gas; a fuel feed duct provided for supplying the fuel cell with fuel gas, the fuel feed duct including an upstream part and a downstream part; a Venturi effect ejector including a high pressure inlet, a low pressure inlet and an outlet, the upstream part of the fuel feed duct being connected to the high pressure inlet of the ejector and the downstream part extending between the ejector outlet and the fuel cell; an off-gas recirculation duct extending between the fuel cell and the low pressure ejector inlet so that, in the presence of a stream of fuel gas coming from the upstream part of the fuel feed duct and passing through the ejector, the ejector draws up off-gas from the recirculation duct and ejects it into the downstream part mixed with the stream of fuel gas coming from the upstream part; a control circuit and a valve arranged in the upstream part of the fuel feed duct and arra

Abstract: The present invention relates to a housing assembly for at least two fuel cells, comprising: a hollow profile-like body (12) extending in an axial direction (z) and being adapted to laterally encompass at least two fuel cells stacked on one another in axial direction (z), and a fastening mechanism to interconnect the body (12) with at least one end plate (18, 28) adapted to support the at least two fuel cells.

Abstract: A fuel cell system including: a fuel cell stack including plural fuel cells sandwiched between two end plates; a fuel supply system supplying a stream of fuel gas to the fuel cell stack; an oxidizer supply system supplying a stream of oxidizer gas to the fuel cell stack; a closed loop coolant circulation system driving a cooling liquid through the fuel cell stack so that the cooling liquid enters the fuel cell stack, absorbs heat from the fuel cells, and exits the fuel cell stack. The coolant circulation system includes a circulation pump driving the cooling liquid, a heat exchanger removing heat from the cooling liquid and for at least partially transferring the heat to the stream of fuel gas and/or the stream of oxidizer gas.

Abstract: A fuel cell system that employs a heat exchanger and a charge air cooler for reducing the temperature of the cathode inlet air to a fuel cell stack during certain system operating conditions so that the cathode inlet air is able to absorb more moisture in a water vapor transfer unit. The system can include a valve that selectively by-passes the heat exchanger if the cathode inlet air does not need to be cooled to meet the inlet humidity requirements. Alternately, the charge air cooler can be cooled by an ambient airflow.

Abstract: A method of operating a PEM fuel cell including an anode feed circuit and a cathode feed circuit for feeding of an anode side with a reactant gas and for feeding a cathode side with a cathode gas. A shut-down mode for shutting down an electricity generating operation of the fuel system includes decreasing the supply of reactant gas and cathode gas in response of a shut-down signal, monitoring an output voltage of at least one cell of a fuel cell stack, monitoring the reactant gas pressure and the cathode gas pressure, electrically shunting of the at least one fuel cell in response of the output voltage reaching a predefined voltage level, at least reducing the pressure of the anode side to a predefined pressure level by means of at least one pump, and filling and/or flushing of at least the anode side with an inert gas.

Abstract: A fuel cell system that employs a technique for safely removing hydrogen gas that accumulates within a cooling fluid reservoir. The fuel cell system includes a fuel cell stack and a compressor for providing airflow to the cathode side of the fuel cell stack. The system also includes an air filter box having an air filter that is in fluid communication with an air pocket in the reservoir. The air intake to the compressor flows through the air filter box, and sucks the gas from the reservoir, which is then sent to the cathode side of the fuel cell stack to be converted to water by the electro-chemical reaction therein.

Abstract: A fuel cell system that employs a technique for safely removing hydrogen gas that accumulates within a cooling fluid reservoir. The fuel cell system includes a fuel cell stack and a compressor for providing airflow to the cathode side of the fuel cell stack. The system also includes an air filter box having an air filter that is in fluid communication with an air pocket in the reservoir. The air intake to the compressor flows through the air filter box, and sucks the gas from the reservoir, which is then sent to the cathode side of the fuel cell stack to be converted to water by the electro-chemical reaction therein.

Abstract: A device and method to convert residual hydrogen present in a fuel cell cooling system into water. An oxygen-bearing fluid is supplied to the cooling system from a source that also has elevated moisture levels to minimize the likelihood that the oxygen-bearing fluid will dry out or otherwise deplete the coolant in the cooling system. One or more valves are included to avoid the formation of adverse pressure gradients that could inhibit the continued supply of the oxygen-bearing fluid to the cooling system.

Abstract: A fuel cell system that employs a heat exchanger and a charge air cooler for reducing the temperature of the cathode inlet air to a fuel cell stack during certain system operating conditions so that the cathode inlet air is able to absorb more moisture in a water vapor transfer unit. The system can include a valve that selectively by-passes the heat exchanger if the cathode inlet air does not need to be cooled to meet the inlet humidity requirements. Alternately, the charge air cooler can be cooled by an ambient airflow.

Abstract: A fuel cell system that employs a recuperative heat exchanger to provide additional cooling for the compressed charge air applied to the cathodes of the fuel cells in the fuel cell stack. The cathode exhaust gas is applied to the recuperative heat exchanger so that the cathode exhaust gas cools the charge air heated by the compressed air. A cathode exhaust gas expander is provided in combination with the recuperative heat exchanger that uses the energy in the heated cathode exhaust gas to power the charge air compressor. An anode exhaust gas combustor can be provided that burns residual hydrogen in the anode exhaust gas to further heat the cathode exhaust gas before it is applied to the expander.

Abstract: A device and method to convert residual hydrogen present in a fuel cell cooling system into water. An oxygen-bearing fluid is supplied to the cooling system from a source that also has elevated moisture levels to minimize the likelihood that the oxygen-bearing fluid will dry out or otherwise deplete the coolant in the cooling system. One or more valves are included to avoid the formation of adverse pressure gradients that could inhibit the continued supply of the oxygen-bearing fluid to the cooling system.

Abstract: A system for reducing the time that it takes a vehicle fuel cell engine to reach its operating temperature at vehicle start-up. The system includes a radiator and a fan, where a cooling fluid from the engine is directed through the radiator where it is cooled by airflow from the fan during high load conditions. The radiator also receives ambient air through a front grill from movement of the vehicle. During vehicle start-up, when the engine is below its optimal operating temperature, the fan is operated in a reverse direction at variable speeds depending on the speed of the vehicle, so that the airflow through the grill that may otherwise convectively cool the engine is significantly reduced or eliminated.

Abstract: A system for reducing the time that it takes a vehicle fuel cell engine to reach its operating temperature at vehicle start-up. The system includes a radiator and a fan, where a cooling fluid from the engine is directed through the radiator where it is cooled by airflow from the fan during high load conditions. The radiator also receives ambient air through a front grill from movement of the vehicle. During vehicle start-up, when the engine is below its optimal operating temperature, the fan is operated in a reverse direction at variable speeds depending on the speed of the vehicle, so that the airflow through the grill that may otherwise convectively cool the engine is significantly reduced or eliminated.

Abstract: A fuel cell system that employs a recuperative heat exchanger to provide additional cooling for the compressed charge air applied to the cathodes of the fuel cells in the fuel cell stack. The cathode exhaust gas is applied to the recuperative heat exchanger so that the cathode exhaust gas cools the charge air heated by the compressed air. A cathode exhaust gas expander is provided in combination with the recuperative heat exchanger that uses the energy in the heated cathode exhaust gas to power the charge air compressor. An anode exhaust gas combustor can be provided that burns residual hydrogen in the anode exhaust gas to further heat the cathode exhaust gas before it is applied to the expander.

Abstract: A fuel cell system that employs a recuperative heat exchanger to provide additional cooling for the compressed charge air applied to the cathodes of the fuel cells in the fuel cell stack. The cathode exhaust gas is applied to the recuperative heat exchanger so that the cathode exhaust gas cools the charge air heated by the compressed air. A cathode exhaust gas expander is provided in combination with the recuperative heat exchanger that uses the energy in the heated cathode exhaust gas to power the charge air compressor. An anode exhaust gas combustor can be provided that burns residual hydrogen in the anode exhaust gas to further heat the cathode exhaust gas before it is applied to the expander.