Abstract: A method of operating the fuel cell stack having an anode side and a cathode side by flowing hydrogen into the anode side and flowing air into the cathode side. The fuel cell produces electricity that is used to operate a primary electrical device. To shut down the stack in one embodiment, the primary electrical device is disconnected from the stack. The flow of air into the cathode side is stopped and positive hydrogen pressure is maintained on the anode side. The fuel cell stack is shorted and oxygen in the cathode side is allowed to be consumed by hydrogen. The inlet and outlet valves of the anode and the cathode sides are closed. Thereafter, the flow of hydrogen into the anode side is stopped and the flow of exhaust from the cathode side is stopped.

Abstract: A three-way diverter assembly with a contoured valve is provided. The three-way diverter assembly includes a housing having a first inlet, a second inlet, a first outlet, and a second outlet. The first inlet and the second inlet are adapted to receive a fluid. The contoured valve is disposed in the housing adjacent the first inlet. The contoured valve is rotatable about an axis from a first positional limit to a second positional limit, and to a plurality of positions therebetween. Fuel cell systems having the three-way diverter assembly for regulating temperature and humidity of a fuel cell stack are also provided.

Abstract: A method for manufacturing a subgasket for a fuel cell stack having a pair of plates disposed in a stack includes the step of positioning a membrane between the plates. The membrane includes an inboard portion and a tortuous form portion. The inboard portion abuts a proton exchange membrane of the fuel cell, and the tortuous form portion abuts each of the plates. The tortuous form portion defines at least one cavity between one of the plates and the membrane. A viscous sealant is injected into the cavity. The sealant is cured to form a compliant bead seal on the membrane.

Abstract: A fuel cell system includes a water vapor transfer unit and a fluid flow distribution feature, the water vapor transfer unit including a first plate having a plurality of first flow channels for receiving a flow of a first fluid therein, and a second plate having a plurality of second flow channels for receiving a flow of a second fluid therein. The fluid flow distribution feature is configured to control at least one of a volume of flow of the first fluid through the first flow channels and a volume of flow of the second fluid through the second flow channels, wherein at least one of a flow distribution of the first fluid across the first plate and a flow distribution of the second fluid across the second plate is varied.

Abstract: A fuel cell stack module that includes a fuel cell stack and an end unit that are part of a thermally integrated assembly. The module also includes a charge air cooler and a WVT unit integrated within the end unit. A cooling fluid is pumped through a line in the end unit and the fuel cell stack by a pump. The cooling fluid is pumped through the charge air cooler to reduce the temperature of the cathode inlet airflow sent to the fuel cell stack. The reduced temperature cathode inlet air from the charge air cooler is sent to the WVT unit where it is humidified. Cathode exhaust gas from the fuel cell stack can be sent to the WVT unit to provide the humidification to humidify the cathode inlet air. A by-pass valve provided within the end unit can be employed to by-pass the WVT unit during cold-starts.

Abstract: Backpressure control valves, methods of controlling backpressure, and fuel cell systems. In one form, the backpressure control valve is mountable in a body that defines an asymmetrical fluid passage. The backpressure control valve may include a shaft cooperative with the body, an asymmetrical blade cooperative with the shaft, and a biasing device operatively connected to the asymmetrical blade, wherein the asymmetrical blade is rotatable between a closed position and an open position. In another form, the method of controlling backpressure may include providing a backpressure control valve including an asymmetrical blade, and rotating the asymmetrical blade between a closed position and an open position. In still another form, the fuel cell system may include a fuel cell, a body that defines an asymmetrical oxidant passage, and a backpressure control valve mountable in the body.

Abstract: A device for minimizing a buoyancy driven convective flow inside a manifold of a fuel cell stack includes a plurality of spaced apart baffle walls. The spaced apart baffle walls are configured to be disposed inside the manifold of the fuel cell stack. The spaced apart baffle walls increase a viscous resistance to the buoyancy driven convective flow inside the manifold.

Abstract: A membrane humidifier for a fuel cell with a wet side plate having a plurality of flow channels formed therein and a dry side plate having a plurality of flow channels formed therein, the flow channels of the wet side plate adapted to facilitate a flow of a wet gas therethrough and the flow channels of said dry side plate adapted to facilitate a flow of a dry gas therethrough, wherein a pressure drop in the humidifier is minimized and a humidification of a proton exchange membrane in the fuel cell is optimized.

Abstract: A device and method to extract water from a moisture-rich fuel cell flowpath to supply other components of a fuel cell system that require water. A water transport unit is integrated into the fuel cell so that the size, weight and complexity of a fuel cell is minimized. In one embodiment, the device includes numerous flowpaths that include an active region and an inactive region. The water transport unit includes a moisture-donating fluid channel and a moisture-accepting fluid channel, where the latter is fluidly connected with a portion of the fuel cell that is in need of humidification. Upon passage of a moisture-donating fluid through the inactive region of the device flowpath, at least some of the water contained therein passes through the water transport unit to a portion of the fuel cell that is in need of humidification.

Abstract: A cooling module for a battery pack assembly is disclosed. The cooling module includes a frame having a plurality of legs forming an opening through a central portion of the frame, at least one of the plurality of legs including a slot formed therethrough. A cooling fin is coupled to the frame. The cooling fin includes a corrugated plate interposed between a first plate and a second plate forming a plurality of fluid flow channels between the first plate and the second plate. The cooling modules are disposed in a stack having at least one battery cell disposed between adjacent cooling modules. The battery cell is in heat transfer communication with the cooling fin of at least one cooling module, wherein the cooling fin facilitates a transfer of heat energy between the battery cell and the flow channels formed in the cooling fin.

Abstract: An integrated charge air heat exchanger for use in a vehicle fuel cell system is provided. The integrated charge air heat exchanger includes a plurality of coolant conduits adapted for a coolant fluid to flow therethrough. The integrated charge air heat exchanger further includes a plurality of heating elements and a plurality of fin elements. One heating element is disposed on a first surface of each of the coolant conduits, and one of the fin elements is disposed on a second surface of each of the coolant conduits. A method for heating the coolant fluid in a first operational mode and cooling a charge air stream in a second operational mode is also provided.

Abstract: A water transfer device can include first and second flow paths separated by a water transfer membrane and a hydrophilic diffusion medium. The hydrophilic diffusion medium is disposed between the water transfer membrane and the first flow path. Water content of a first fluid stream flowing through the first flow path is transferred through the diffusion medium and water transfer membrane and into a second fluid stream flowing through the second flow path. The hydrophilic diffusion medium is operable to absorb liquid water in the first fluid stream and hold the absorbed liquid water in contact with the water transfer membrane. The hydrophilic diffusion medium is also operable to diffuse water vapor in the first fluid stream and transport the water vapor to the water transfer membrane. The water transfer membrane transfers the water in contact therewith to the second fluid stream flowing through second flow path.

Abstract: A plate for a membrane humidifier for a fuel cell system is disclosed, wherein the plate includes a top layer formed from a diffusion medium and a bottom layer formed from a diffusion medium with an array of substantially planar elongate ribbons disposed therebetween.

Abstract: A fuel cell system is provided including a fuel cell stack including at least one fuel cell, a first compression plate disposed adjacent the fuel cell stack, a second compression plate disposed adjacent the fuel cell stack, and a compression enclosure apparatus. The compression enclosure apparatus comprises a unitary main body having first and second fastening points and an intermediate portion, wherein the first fastening point and the second fastening point are coupled to the first compression plate and the intermediate portion is disposed adjacent the second compression plate. The fuel cell system minimizes a number of components required to retain compression of the fuel cell stack, minimizes a mass of the fuel cell system, and simplifies a design of the fuel cell system. Also provided is a method for assembling the fuel cell system.

Abstract: A fuel cell system comprises a main body including a first partial header and a fastening point. The main body is adapted to be coupled to a plurality of plates forming a fuel cell stack, allowing a single plate design to be used for multiple fuel cell stack lengths having a large differential of energy requirements, affording a durable alignment mechanism for the fuel cell stack, and providing integration flexibility for components and configurations of the fuel cell system.

Abstract: At least one positive temperature coefficient element is used to efficiently control fuel cell voltage at startup and shutdown making the fuel cell more efficient and protecting the electro catalyst layer.

Abstract: A membrane humidifier for a fuel cell with a wet side plate having a plurality of flow channels formed therein and a dry side plate having a plurality of flow channels formed therein, the flow channels of the wet side plate adapted to facilitate a flow of a wet gas therethrough and the flow channels of said dry side plate adapted to facilitate a flow of a dry gas therethrough, wherein a pressure drop in the humidifier is minimized and a humidification of a proton exchange membrane in the fuel cell is optimized.

Abstract: A membrane humidifier for a fuel cell is disclosed, wherein a pressure drop in the humidifier is minimized and a humidification of a proton exchange membrane in the fuel cell is optimized.

Abstract: A fuel cell assembly and method is disclosed for the mixing and heating of hydrogen and air in the fuel cell assembly and introducing the heated hydrogen and air to the fuel cell assembly during a starting operation to heat the fuel cell assembly to militate against vapor condensation and ice formation in the fuel cell assembly.

Abstract: A fuel cell assembly and method is disclosed for the mixing and heating of hydrogen and air in the fuel cell assembly and introducing the heated hydrogen and air to the fuel cell assembly during a starting operation to heat the fuel cell assembly to militate against vapor condensation and ice formation in the fuel cell assembly.