Abstract: A fuel cell system (10) that includes with a polymer electrolyte fuel cell (22) having a polymer electrolyte membrane is provided with a determining portion that determines whether a moisture content in the polymer electrolyte membrane is low, and an anode gas pressure regulating portion that sets a gas pressure on an anode side of the fuel cell lower than a set value of the gas pressure on the anode side during steady operation in which the moisture content is not low, when it is determined that the moisture content is low.

Abstract: A fuel cell system including a gas recycling and re-pressurizing assembly. In one embodiment, the fuel cell system includes a fuel cell stack, the stack having an oxygen outlet and an oxygen inlet. The fuel cell system additionally includes two gas/water separator tanks, each of the tanks containing a quantity of water and a quantity of oxygen gas. Both tanks are capable of being fluidly connected to either the oxygen inlet or the oxygen outlet of the fuel cell stack. In addition, the two tanks are connected to one another so that water may be transferred back and forth between the two tanks. The system also includes a pump for transferring water back and forth between the tanks.

Abstract: An apparatus for recirculation of a cathode gas in a fuel cell arrangement having a cathode gas supply for supplying the cathode gas to a cathode area, and a cathode gas outlet for carrying the partially consumed cathode gas out of the cathode area, includes a recirculation line for recirculation of the partially consumed cathode gas from a junction point in the cathode gas outlet into a supply point in the cathode gas supply. Blocking apparatus is provided to block the cathode gas supply in the flow direction upstream of the supply point and to block the cathode gas outlet in the flow direction downstream from the junction point, such that a closed circuit for the partially consumed cathode gas is formed when the blocking apparatus is closed.

Abstract: A multi-unit fuel cell system that includes a common-use reforming unit configured to supply hydrogen to multiple fuel cell units that are installed in multiple units, such as apartments within an apartment building. In one example embodiment, a fuel cell system including a common-use reforming unit and multiple fuel cell units is disclosed. The common-use reforming unit is configured to supply hydrogen to the plurality of fuel cell units. Each fuel cell unit includes a stack unit, an air supplying unit, an integral heat exchange unit, a hot-water supplying unit, an auxiliary heat supplying unit, and an electric output unit.

Abstract: A unit consisting of a fuel cell, provided with a first ion-exchange membrane, and an electrolysis cell, equipped with a second ion-exchange membrane, capable of operating as an electrochemical hydrogen pump in which the electrolysis cell sucks in the discharge gas of the fuel cell anodic compartment which contains hydrogen as the main component, ionizes the hydrogen on a suitable anodic catalyst, sends the so formed protons across the second ion-exchange membrane to a suitable cathodic catalyst where the protons are reconverted to hydrogen which is mixed to the fuel cell hydrogen feed.

Abstract: A fuel cell system including a gas recycling and re-pressurizing assembly. In one embodiment, the fuel cell system includes a fuel cell stack, the stack having an oxygen outlet and an oxygen inlet. The fuel cell system additionally includes two gas/water separator tanks, each of the tanks containing a quantity of water and a quantity of oxygen gas. Both tanks are capable of being fluidly connected to either the oxygen inlet or the oxygen outlet of the fuel cell stack. In addition, the two tanks are connected to one another so that water may be transferred back and forth between the two tanks. The system also includes a pump for transferring water back and forth between the tanks. In use, water is pumped from one of the tanks to the other until all of the oxygen gas present within the water-receiving tank is forced out of that tank and is conducted back to the oxygen inlet of the fuel cell stack.

Abstract: A stop method for a fuel cell system that includes a fuel cell unit in which hydrogen is supplied to an anode, and air is supplied to a cathode so as to generate electrical power via an electrochemical reaction. The stop method includes the steps of stopping supply of hydrogen to the anode, and supplying air to the anode so as to discharge water remaining at the anode.

Abstract: An inlet fuel distributor (10-10d) has a permeable baffle (39, 54, 54a, 60) between a fuel supply pipe (11, 83) and a fuel inlet manifold (12, 53, 53a, 63) causing fuel to be uniformly distributed along the length of the fuel inlet manifold. A surface (53, 68) may cause impinging fuel to turn and flow substantially omnidirectionally improving its uniformity. Recycle fuel may be provided (25, 71) into the flow downstream of the fuel inlet distributor. During startup, fuel or inert gas within the inlet fuel distributor and the fuel inlet manifold may be vented through an exhaust valve (57, 86) in response to a controller (58, 79) so as to present a uniform fuel front to the inlets of the fuel flow fields (58).

Abstract: A fuel cell system is provided. The fuel cell system includes a fuel tank, a fuel supply unit, a fuel cell stack, a liquefied recycling unit, a liquid level modulation unit, a sensing unit and a control unit. The fuel supply unit supplies a first fuel to the fuel tank. The fuel tank provides a second fuel to the fuel cell stack, and the fuel cell stack generates a first gas. The liquefied recycling unit liquefies the first gas, transforming the first gas into a recycled fluid. The liquid level modulation unit guides the recycled fluid into the fuel tank to maintain a stable fuel level of the second fuel in the fuel tank. The sensing unit senses a current signal provided by the fuel cell stack. The control unit calculates a current quantity according to the current signal to supply the first fuel to the fuel tank.

Abstract: The potential energy from a hydrogen tank is used in a gas jet pump, which draws in anode waste gas via an inlet and recirculates it to an anode inlet. To ensure that this system operates effectively even under low loads, a part of the waste gas is supplied to a compressor, and the compressed waste gas is supplied to the motive jet inlet of a gas jet pump, which may be the same one to which the hydrogen from the tank is also supplied. Different gas jet pumps may also be used, for the hydrogen from the tank on the one hand, and the compressed waste gas on the other hand.

Abstract: A direct oxidation fuel cell (DOFC) system comprises at least one fuel cell assembly including a cathode and an anode with an electrolyte positioned therebetween; a source of liquid fuel in fluid communication with an anode inlet; an oxidant supply in fluid communication with a cathode inlet; a liquid/gas (L/G) separator in fluid communication with anode and cathode outlets for: (1) receiving unreacted fuel and liquid and gaseous products of electrochemical reactions at the cathode and anode, and (2) supplying the unreacted fuel and liquid product to the inlet of said anode; and a control and/or regulation system for determining a fuel efficiency value of the DOFC system during operation and determining and regulating and/or controlling oxidant stoichiometry of the DOFC system at an appropriate value in response to the determined fuel efficiency value.

Abstract: A device and method to predict and regulate nitrogen concentration in a flow shifting system. In one aspect of the system, a bleed valve fluidly coupled to multiple fuel cell stacks is used to reduce the presence of nitrogen in an anode flowpath. One or more sensors can be used to measure voltage within one or both of the fuel cell stacks. By assessing fuel cell voltage changes within the anode flowpath and equating such changes with nitrogen fraction buildup, the system can manipulate the bleed valve at appropriate times to improve system operability. In one form of equating the sensed voltage changes with the nitrogen fraction buildup, a predictive algorithm can be used by a logic device in a controller to compare the sensed voltage so that the controller instructs the bleed valve when to open and close. In a variation, the controller can compare the sensed voltages against stored data rather than rely on a formula or related algorithm.

Abstract: A fuel cell stack (1) performs power generation using an anode gas having hydrogen as its main component, and after a power generation reaction, the anode gas is discharged as anode effluent. The anode effluent is re-circulated into the anode gas through a return passage (5). The return passage (5) comprises a purge valve (8) which discharges the anode effluent to the outside of the passage. In this invention, calculation of a first energy loss caused by an increase in non-hydrogen components in the anode gas while the purge valve (8) is closed (S7, S28), and calculation of a second energy loss which corresponds to the amount of hydrogen lost from the anode gas by opening the purge valve (8) (S8, S29) are performed. By opening the purge valve (8) when the second energy loss equals or falls below the first energy loss, the start timing of purging is optimized.

Abstract: A gas-liquid separation system includes a housing at which a gas inlet and a gas outlet are provided; a separation pipe contained in the housing; a separation membrane provided in the separation pipe; and a pump configured to inject a gas into the housing through the gas inlet from an outside of the housing to the gas outlet.

Abstract: In a fuel cell system having an ejector downstream a hydrogen pump, the pressure of a hydrogen-off gas is efficiently increased with a simple configuration.

Abstract: The invention is a hydrogen passivation shut down system for a fuel cell power plant (10). An anode flow path (24) is in fluid communication with an anode catalyst (14) for directing hydrogen fuel to flow adjacent to the anode catalyst (14), and a cathode flow path (38) is in fluid communication with a cathode catalyst (16) for directing an oxidant to flow adjacent to the cathode catalyst (16) of a fuel cell (12). Hydrogen fuel is permitted to transfer between the anode flow path (24) and the cathode flow path (38). A hydrogen reservoir (66) is secured in fluid communication with the anode flow path (24) for receiving and storing hydrogen during fuel cell (12) operation, and for releasing the hydrogen into the fuel cell (12) whenever the fuel cell (12) is shut down.

Abstract: The pump comprises a pump body, a control member, an elastic member, and blades. The pump body has a holding space, one or more pump inlets, and one or more pump outlets. The holding space, the pump inlets, and the pump outlets communicate with each other. The pump outlets communicate with a fuel outlet of the fuel storage device; while the pump inlets communicate with a fuel reservoir of the fuel storage device. The control member passes through the fuel storage device and is rotatably set in the holding space. The elastic member is set fixed on the pump body and connects with the control member. The blades are set in the holding space and connect with the control member. Thereby, no extra energy is needed for the pump to transport the fuel from the fuel reservoir to the fuel cell.

Abstract: A method of operating a fuel cell system includes providing a fuel inlet stream into a fuel cell stack, operating the fuel cell stack to generate electricity and a hydrogen containing fuel exhaust stream, separating at least a portion of hydrogen contained in the fuel exhaust stream using a cascaded electrochemical hydrogen pump, such as a high temperature, low hydration ion exchange membrane cell stack having at least two membrane cells arranged in process fluid flow series, and providing the hydrogen separated from the fuel exhaust stream into the fuel inlet stream.

Abstract: To provide a fuel cell and an oxidant distributing plate for the fuel cell. A water created in the fuel cell is used to humidify an oxidant gas and/or a fuel flowing in an opposite passage opposite to a MEA. The fuel cell includes a MEA 1, an oxidant distributing plate 3 disposed facing to an oxidant pole for supplying an oxidant gas thereto, and a fuel distributing plate 4 disposed facing to an fuel pole for supplying the fuel thereto. At least one of the oxidant distributing plate 3 and the fuel distributing plate 4 is provided with an opposite passage 31, 41 formed on an opposite surface opposite to the MEA, and a reaction passage 32, 42 formed on a facing surface facing to the MEA, and communicated with the opposite passage 31, 41.

Abstract: One of the main objects in providing optimal mass exchange for fuel cells, especially mobile fuel cells, is anode gas supply to fuel cell stack based on stoichiometric characteristics depending on variable loads and anode gas recirculation. External loads may vary in wide range and arbitrary change, thus complicate the optimal mass exchange in fuel cell stack. A new original technology is disclosed for anode gas supply using a multi-stage ejector. This technology, an ejector design and control system allow increasing fuel cell efficiency with quick loads changing from minimal to maximal as well as at cold start.

Abstract: An electrical power plant that includes a fuel cell and at least one recycle system for recycling at least a first reactant, for reuse by the fuel cell. The fuel cell discharges a first exit stream that includes the first reactant and inerts. The recycle system comprises a separator that receives the first exit stream from the fuel cell and separates the first reactant contained in the first exit stream from inerts contained in the exit stream. The separated first reactant is directed back to the fuel cell for reuse. The remaining inerts and unseparated first reactant are discharged by the separator and then recirculated back into the separator, without progressing through the fuel cell, to separate additional first reactant from the inerts.

Abstract: A parallel dual stack fuel cell system having anode recirculation includes a first fuel cell stack and a second fuel cell stack. Each of the first and second fuel cell stacks includes a gas outlet line connected to an anode outlet unit. The anode outlet unit functions to release wet H2/N2 gaseous mixture from the system. A second water separator is provided between the anode outlet unit and gas inlet lines to the first and second fuel cell stacks to increase removal of water droplets prior to a recirculation pump.

Abstract: A fuel cell system that is capable of handling gasified fuel in an aqueous solution tank includes an aqueous solution tank which holds fuel aqueous solution, a fuel cell including an anode supplied with the fuel aqueous solution from the aqueous solution tank, and a cathode provided with a catalyst containing platinum Pt, an air supplying unit including an air pump and arranged to supply air to the cathode in the fuel cell, and a gas guide arranged to add a gas containing gasified methanol from the aqueous solution tank to the air to be sent to the cathode.

Abstract: A fuel cell system and method for driving the same is disclosed. In one embodiment, the fuel cell system includes i) a fuel supply unit, ii) a fuel cell stack in fluid communication with the fuel supply unit, wherein the fuel cell stack has a fuel inlet and a fuel outlet and iii) a bypass pipe configured to transfer fuel received from the fuel supply unit to a fuel outflow pipe connected to the fuel outlet. In one embodiment, the driving method includes i) receiving fuel from a fuel supply unit, ii) transferring the received fuel to a fuel outflow pipe connected to a fuel outlet of a fuel cell stack and iii) discharging non-reacted fuel from a fuel inlet of the fuel cell stack.

Abstract: A fuel cell system according to exemplary embodiments of the present invention includes a fuel cell stack that generates electrical energy through the electrochemical reaction of fuel and oxidant, a fuel supply unit for supplying the fuel to the fuel cell stack, and an oxidant supply unit for supplying the oxidant to the fuel cell stack. The fuel supply unit includes a fuel permeation membrane between a space where fuel recovered from the fuel cell stack is positioned and a space where stored fuel is positioned. The fuel cell system enables easy control of the concentration of fuel supplied to the fuel cell stack.

Abstract: In a fuel cell power plant (9) air bleed is provided to the anode flow fields (13) of a stack (11) of fuel cells by introducing the air into the recycle loop (23, 24) upstream of the recycle drive (25). The source of air may be the cathode air supply device (31) that provides oxidant reactant gas to the cathode flow fields (14), or a separate, low pressure, low flow air pump (48) or a separate low pressure, low flow pump (45) connected from the cathode air supply devise (31) through flow controllers (41, 42) to the pressure side of the recycle loop (23, 24) at the exhaust of the anode flow fields (13).