Abstract: A fuel cell system having a fuel cell, coolant circulating means which circulates cooling water into the fuel cell, temperature sensors which detect a cooling water outlet temperature and a cooling water inlet temperature, and temperature adjusting means which adjusts a temperature of the fuel cell by controlling a flow rate of the coolant on the basis of the cooling water outlet temperature, is characterized by including abnormality determining means which determines whether or not abnormality occurs in the temperature sensor, and coolant temperature estimating means which, when the abnormality determining means determines that abnormality occurs in the temperature sensor, estimates the cooling water outlet temperature on the basis of physical information relating to operating states of the fuel cell.

Abstract: Fuel cell stacks and systems with thermal management systems to deliver a liquid heat exchange fluid into thermal communication with the stack and thereafter recycle the stream. In some embodiments, the system is adapted to selectively apportion the recycled liquid stream between a stream that, prior to reuse as a heat exchange stream, is returned to a fluid reservoir and/or selectively cooled, and/or selectively returned to the reservoir and mixed with heat exchange fluid in the reservoir, and a stream that is returned into thermal communication with the stack without returning the stream to the reservoir and/or without heating or cooling and/or without being mixed with additional heat exchange fluid. In some embodiments, the system is adapted to automatically apportion the recycled stream responsive to its temperature. In some embodiments, the system includes a thermostatic valve and/or selectively apportions the recycled stream without requiring an electronic controller or manual input.

Abstract: A method is provided for reducing degradation in a fuel cell assembly, including at least one fuel cell with a PBI membrane, during standby, operation. The method may include electrochemically consuming an oxidant from a cathode coupled to the PBI membrane in response to a disconnection of an external load and supplying fuel to remove or electrochemically consume any back-diffused oxidant to the associated fuel cell sufficient to replace or consume the back-diffused oxidant while the external load is removed, and/or also may include controlling a standby temperature of the fuel cell. In this way, it may be possible to avoid increased cell voltage decay associated with degradation of the PBI in a simple and cost effective system.

Abstract: A method is provided for reducing degradation in a fuel cell assembly, including at least one fuel cell with a PBI membrane, during standby, operation. The method may include electrochemically consuming an oxidant from a cathode coupled to the PBI membrane in response to a disconnection of an external load and supplying fuel to remove or electrochemically consume any back-diffused oxidant to the associated fuel cell sufficient to replace or consume the back-diffused oxidant while the external load is removed, and/or also may include controlling a standby temperature of the fuel cell. In this way, it may be possible to avoid increased cell voltage decay associated with degradation of the PBI in a simple and cost effective system.

Abstract: A hydrogen generator includes: a reformer configured to generate a hydrogen-containing gas by a reforming reaction between a raw material and water; a heater configured to combust at least a part of the hydrogen-containing gas to supply heat necessary for the reforming reaction to the reformer; a combustion detector configured to detect a combustion state of the heater; a raw material supplier configured to supply the raw material; a water supplier configured to supply the water; and an operation controller. When stopping the hydrogen generator, the operation controller causes the raw material supplier to stop operating, the water supplier to stop operating in a case where the combustion detector detects extinction of flame, and the raw material supplier to start operating to supply the raw material to the hydrogen generator in a case where the reforming temperature detector detects a temperature equal to or lower than a reference temperature.

Abstract: A fuel cell system includes a fuel cell stack, a heat exchanger, an evaporator, a reformer, and a combustor. A fluid unit including at least the heat exchanger, the evaporator, and the reformer is provided at one end of the fuel cell stack in a stacking direction. The combustor is provided inside the evaporator The combustor has a combustion gas path for discharging a combustion gas produced in the combustor. The reformer is provided at a position in the middle of the combustion gas path.

Abstract: A fuel cell cooling system (10) includes a fuel cell (12) having a liquid loop (24) that produces water vapor. An antifreeze cooling loop (38) includes an inductor (40) that receives the water vapor and introduces the water vapor to an antifreeze. The water is separated (48) from the antifreeze and returned to the liquid cooling loop as liquid water (50) after the mixture of condensed water vapor and antifreeze has passed through a radiator (46). Water in the liquid cooling loop (24) exits the fuel cell (12) and passes through a restricting valve (32) thereby lowering the pressure of the water A flash cooler (34) downstream from the restricting valve collects the water vapor and provides it to the inductor (40) in the antifreeze cooling loop (38).

Abstract: A fuel cell system of the present invention is provided with a fuel cell, a fuel gas supply system that supplies a fuel gas to the fuel cell, and an oxidant gas supply system that supplies an oxidant gas to the fuel cell, and, when operation end processing is started, a flow rate of the fuel gas supplied to the fuel cell is increased only by a predetermined amount that is determined based on a temperature environment of the fuel cell system. As a result, when the operation of the fuel cell system is ended, the fuel gas at the optimum flow rate in accordance with the temperature environment is provided, thereby efficiently preventing deterioration of the fuel cell after the end of the operation.

Abstract: A method of operating a fuel cell system comprising a fuel cell and a compressor that provides air to the fuel cell. The method comprises sensing a temperature indicative of the temperature of a fuel cell, providing a restriction in an air flow path to the fuel cell when the sensed temperature is below a threshold, and increasing the speed of the compressor to provide a desired air flow to the fuel cell. In at least some implementations, increasing the speed of the compressor increases the power drawn from the fuel cell to power the compressor and helps to increase the heat of the fuel cell. The increased speed of the compressor can also result in warmer air flow from the compressor that can further increase the temperature of the system components.

Abstract: A fuel cell stack includes a stack body formed by stacking a plurality of power generation cells. A terminal, an insulating plate, and an end plate are provided at one end of the stack body, and a terminal, an insulating plate, and an end plate are provided at the other end of the stack body. Each of the terminals includes an electrically conductive plate member, and an electrically conductive rod terminal joined integrally with the electrically conductive plate member. A joint portion joining the electrically conductive plate member and the electrically conductive rod terminal is formed by friction stir welding.

Abstract: A fuel cell cooling device has a cooling loop for circulating a coolant fluid. At least during the operation of the fuel cell, an ion extraction medium that is in the liquid state is provided. A method for cleaning a coolant with a corresponding fuel cell cooling device is provided as well.

Abstract: A coolant composition for a fuel cell unit, which contains at least one aliphatic alcohol having unsaturated bonds in the molecules having 2 to 20 carbon atoms each. The coolant composition maintains the electrical conductivity of the coolant at 10 ?S/cm or below as well as the fluctuation of the electrical conductivity within the range of 0 to 10 ?S/cm.

Abstract: The present invention provides a current collector of an end plate for a fuel cell and a method for controlling the same, in which a plurality of current collector plates having different resistance values is mounted on an end plate so that the current of a fuel cell is consumed during cold start and during low power operation to improve cold startability of the fuel cell and, further, the durability of a membrane electrode assembly (MEA) is improved due to an increase in voltage during low power operation.

Abstract: A fuel cell system and a method for operating the same are disclosed. In one embodiment, a fuel cell system includes a fuel supplier, a reformer for reforming a fuel supplied from the fuel supplier into hydrogen gas by a reforming reaction, and a fuel cell stack for generating electrical energy by an electrochemical reaction between the hydrogen gas and an oxidizing agent. When the fuel cell system is to be stopped, the reforming reaction of the reformer and the electrochemical reaction of the fuel cell are stopped and a portion of unreformed fuel is fed to the reformer and the fuel cell stack. Residual hydrogen is reacted and residual power from the fuel cell stack is dissipated by a power dissipation circuit. By largely removing hydrogen from the fuel cell stack on a stopped condition, reactions that are detrimental to the fuel cell membrane are reduced.

Abstract: A reformer for a fuel cell system includes a heating source for generating heat by a reaction of a fuel and an oxidant using an oxidizing catalyst, and a reforming reaction part for generating hydrogen by a reforming catalyst reaction. The oxidizing catalyst includes a solid acid, including a strong acid ion and an inorganic oxide, and a platinum-based metal. The reformer for a fuel cell system can start a fuel oxidation catalyst reaction at a low temperature with the heating source having a simplified structure.

Abstract: A fuel cell includes a plurality of electrolyte electrode assemblies and a pair of separators sandwiching the electrolyte electrode assemblies. A fuel gas supply channel formed by a channel member fixed to the separator is connected to a fuel gas inlet formed in an inner end of a trapezoidal section. Unburned hydrogen in an exhaust fuel gas consumed in the reaction at the anode, and discharged from the fuel gas channel to an oxygen -containing gas supply unit, is mixed with an oxygen-containing gas before consumption, burned, and then supplied to an oxygen-containing gas channel.

Abstract: The amount of moisture discharged from within a fuel cell is increased by a simple construction. The fuel cell system includes a fuel cell for generating electrical power after causing an anode to receive a hydrogen-containing anode gas and causing a cathode to receive an oxygen-containing cathode gas; an exhaust gas valve provided downstream of the fuel cell in a gas circulation system that supplies an anode gas to the fuel cell; a regulator that is provided upstream of the fuel cell in the gas circulation system and raises gas pressure in the gas circulation system; and an ECU that opens the exhaust gas valve, with the gas pressure kept raised to a level higher than in normal times by use of the regulator. As a result of this, it is possible to increase the gas flow rate and flow velocity within the fuel cell, and it becomes possible to increase the discharge amount of moisture stagnating within the fuel cell.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A barrier layer for a fuel cell assembly is disclosed, the barrier layer having a thermally insulating layer having a first surface and a second surface, and an electrically conducting layer formed on the first surface of the thermally insulating layer. The thermally insulating layer may include a plurality of apertures formed therethrough, and the electrically conducting layer may be formed on a second surface of the thermally insulating layer and on the walls of the thermally insulating layer forming the apertures.

Abstract: A hybrid voltage supply apparatus, a method of controlling the same, and an electronic system employing the hybrid voltage supply apparatus as a power supply are provided. The hybrid voltage supply apparatus includes a hybrid voltage supply apparatus including a main power supply, an auxiliary power supply, and a first voltage adjustment unit which operates in any one of a feed-forward driving mode and a feed-back driving mode according to at least one operating parameter of the main power supply, and adjusts an output voltage of the main power supply to a first predetermined DC voltage.

Abstract: A fuel cell supplies power to a load under nominal conditions. A method for using the fuel cell comprises at least one regeneration step of the performances of the fuel cell by temporarily lowering its temperature below the nominal operating temperature. The regeneration step, performed during a preset time, can be triggered periodically or when the voltage at the terminals of the fuel cell or the fuel cell temperature is lower than a threshold. The performances of the fuel cell, in particular its voltage, can thereby be maintained substantially constant during long periods of use.

Abstract: A method for refilling a hydrogen reservoir comprising a first hydrogen-storing material comprises establishing a fluid connection between the hydrogen reservoir and a cartridge containing a second hydrogen-storing material. The second hydrogen-storing material releases hydrogen at a pressure sufficient to charge the first hydrogen-storing material. Some embodiments involve heating the second hydrogen-storing material and/or allowing heat to flow between the first and second hydrogen-storing materials.

Abstract: An object of the present invention is to provide a fuel cell system in which a noise and a vibration of a compressor can be suppressed. In order to achieve the above object, the present invention provides a fuel cell system including a fuel cell; a compressor for supplying an oxidant gas to the fuel cell, having a first rotational speed region within which as a rotational speed increases, a noise becomes greater than a predetermined value, and a second rotational speed region within which as the rotational speed increases, the noise becomes equal to or less than the predetermined value; and a compressor controller for controlling the compressor by calculating a command rotational speed for commanding the compressor based on a required amount of power generation.

Abstract: The invention concerns a monopolar fuel cell endplate (4) of the type with proton exchanging membrane consisting of a cathode or anode monopolar half-plate (41) attached to a closure plate (42). The monopolar half-plate comprises, in its central part, a cathode or anode active region (411), and, at its periphery, at least two oxidant boxes, if the monopolar half-plate is cathodic, or fuel boxes, if the monopolar half-plate is anodic. Each oxidant or fuel box comprises at least one channel (414) emerging outside the active region (411) to enable oxidant or fuel to be circulated outside the monopolar plate on the monopolar plate side, the oxidant or fuel boxes not comprising an opening emerging into the central region of the closure plate, such that the central part of said closure plate is not swept either with fuel or with oxidant.

Abstract: Apart from electrical energy, nowadays the main engines also supply pneumatic and hydraulic energy to the aircraft, using corresponding media. Apart from mechanical disadvantages this results in reduced engine efficiency in relation to thrust, fuel consumption and weight. According to an embodiment of the present invention an energy supply system for aircraft is provided, comprising a fuel cell arrangement and an electrical energy distribution device. In this way it is possible to replace all the energy generating systems of the engines, which provide energy for the aircraft systems, except for the starter generator, as a result of which the efficiency of the individual engines is improved. Furthermore, the efficiency of onboard energy generation is improved, which in the final analysis results in reduced fuel consumption.

Abstract: A fuel cell system is provided comprising: a reformer for generating hydrogen from hydrogen-containing fuel; and at least one electricity generator for generating electric energy through an electrochemical reaction of hydrogen and oxygen. The reformer includes a main body in which a plurality of reaction sections for generating hydrogen from hydrogen-containing fuel is integrally formed. A heating section is disposed in contact with the main body in order to supply different amounts of thermal energy to the plurality of reaction sections.

Abstract: A method of operating fuel cell system includes generating electricity by a fuel cell using fuel gas and oxidizing gas and allowing cooling water to flow in the fuel cell and thereby cooling the fuel cell. The method includes transferring moisture from exhaust gas to supply gas using a first humidifier, the exhaust gas being discharged from the fuel cell, the supply gas being supplied to the fuel cell, and transferring moisture from the cooling water to the supply gas humidified using a second humidifier. The method includes at least one of detecting humidity of the supply gas humidified, detecting temperature of the cooking water, detecting the flow rate of the supply gas and detecting the amount of electricity generated by the fuel cell. The method also includes controlling the humidity of the supply gas humidified based on the value detected.

Abstract: A method is provided for reducing degradation in a fuel cell assembly, including at least one fuel cell with a PBI membrane, during standby, operation. The method may include electrochemically consuming an oxidant from a cathode coupled to the PBI membrane in response to a disconnection of an external load and supplying fuel to remove or electrochemically consume any back-diffused oxidant to the associated fuel cell sufficient to replace or consume the back-diffused oxidant while the external load is removed, and/or also may include controlling a standby temperature of the fuel cell. In this way, it may be possible to avoid increased cell voltage decay associated with degradation of the PBI in a simple and cost effective system.

Abstract: A coolant subsystem for use in a fuel processor and a method for its operation are disclosed. In accordance with a first aspect, the coolant subsystem is separate from the feed to the processor reactor and is capable of circulating a coolant through the processor reactor. In accordance with a second aspect, the constituent elements of the fuel processor are housed in a cabinet, and the coolant subsystem is capable of cooling both the processor reactor and the interior of the cabinet. In various alternatives, the fuel processor can be employed to reform a fuel for a fuel cell power plant and/or may be used to provide thermal control for unrelated mechanical systems.

Abstract: A dual stack fuel cell system comprising a first fuel cell stack comprising a first anode side, adapted to receive fuel and to output a first anode exhaust, and a first cathode side, a second fuel cell stack comprising a second anode side, adapted to receive processed anode exhaust derived from the first anode exhaust and to output a second anode exhaust, and a second cathode side, adapted to receive oxidant gas and to output a first cathode exhaust, wherein the first cathode side receives at least the first cathode exhaust outputted from the second cathode side; and wherein the first fuel cell stack includes indirect internal reforming and the second fuel cell stack may not include any indirect internal reforming.

Abstract: A system and method for combining an additive with a carrier fluid in a spray nozzle. The carrier fluid is fed to one or more nozzles that include an embedded Venturi. The Venturi includes an induction port connected to an additive supply. As the carrier fluid flows through the nozzle, the flow creates a vacuum or suction force that draws in the additive. Of particular advantage, the concentration of the additive combined with the carrier fluid can be maintained constant even if the flow rate of the carrier fluid varies. The system and process are particularly well suited for spraying fields, such as crop fields or orchards, with an agrochemical.

Abstract: One exemplary embodiment includes a fuel cell comprising a polymer electrolyte membrane sandwiched between an anode and a cathode, a gas diffusion layer disposed over each of the cathode and the anode, a gas flow distributor layer disposed over the gas diffusion layer on both the anode and cathode sides, and optionally a coolant plate disposed over the gas flow distributor layer. The thermal resistance of the combined gas diffusion layer and gas flow distributor layer on the anode and/or cathode side is sufficient to allow the cathode catalyst layer to operate at an elevated temperature to effectively evaporate water produced at the cathode.

Abstract: A fuel cell and an electronic apparatus with same mounted thereon are provided. The fuel cell includes a power generation unit provided with a conduit for an oxidant gas containing at least oxygen, a heat radiation unit connected to the power generation unit so as to radiate heat from the power generation unit, a gas flow means for causing the oxidant gas to flow in the conduit, and a cooling means driven independently from the gas flow means so as to cool the heat radiation unit. By independently controlling the driving of the gas flow means and the cooling means, the fuel cell can be driven in such a manner that the temperature of the power generation unit and the amount of water remaining in the power generation unit are regulated into preferable conditions. Furthermore, it is possible to provide a fuel cell and an electronic apparatus with the same mounted thereon in which power generation can be performed stably and various apparatuses are contained therein in a compact form.

Abstract: A fuel cell system includes a first fuel cell stack, a second fuel cell stack arranged in a cascade configuration with the first fuel cell stack, and at least one hydrocarbon fuel reformer which is thermally integrated with at least a portion of the first stack. The system is configured such that in operation, at least partial reformation of hydrocarbon fuel occurs prior to entry into the first stack or in the first stack, and the second stack uses fuel exhaust from the first stack as fuel. A method of operating the fuel cell system includes reforming a hydrocarbon fuel to form a reformed fuel while cooling at least a portion of a first fuel cell stack, generating electricity in the first fuel cell stack using the reformed fuel, providing a fuel exhaust stream from the first fuel cell stack into a second fuel cell stack, and generating electricity in the second fuel cell stack using the fuel exhaust stream from the first fuel stack as a fuel.

Abstract: A fuel cell system includes a fuel cell stack, a combustor, a heat exchanger, and heat utilization equipment. Further, the fuel cell system includes a bypass channel and a control device. In the bypass channel, at least some of heat medium produced in the combustor is supplied to the heat utilization equipment, bypassing the heat exchanger. The control unit adjusts the supply of the heat energy supplied to the fuel cell stack through an oxygen-containing gas heated by the heat exchanger, and adjusts the heat energy of the heat medium which passes through the bypass channel, and which is supplied to the heat utilization equipment.

Abstract: The invention concerns an energy production unit, of electric energy in particular, comprising a fuel cell (1) and a heat source (2) thermally coupled to the fuel cell (1) at least to allow the rise in temperature of this fuel cell (1). According to the invention, it is provided that the heat source (2) comprises a radiating burner (20), that the fuel cell (1) is confined within a thermal insulation enclosure itself heated by the combustion gases (F) derived from the burner (20), and that this unit also comprises temperature regulation means (4) capable of controlling, from around 200° C. to at least 800° C., the temperature of the combustion gases (F) heating the enclosure 3.

Abstract: The invention relates to fuel cell devices and systems, and methods of using and making fuel cell devices and systems. The fuel cell devices include an elongate ceramic substrate, such as a rectangular or tubular substrate, the length of which is the greatest dimension such that thermal expansion is exhibited along a dominant axis that is coextensive with the length. A reaction zone is positioned along a first portion of the length for heating to an operating reaction temperature, and at least one cold zone is positioned along a second portion of the length for operating at a temperature below the operating reaction temperature. There are one or more fuel passages and one or more oxidizer passages extending within an interior solid support structure of the elongate substrate, each having an associated anode and cathode, respectively, which are separated by an electrolyte. The passages include a neck-down point.

Abstract: A system and method for improving fuel cell system start-up reliability. The method includes determining if the resistance of the membranes in a fuel cell stack is too high, where the reliability of system start-up will be reduced, and if so, providing one or more remedial actions to help ensure that the start-up is more reliable. In one embodiment, the system and method determine that the fuel cell membranes are to dry based on whether a high frequency measurement of the fuel cell stack exceeds a predetermined HFR threshold. If the HFR threshold has been exceeded, a special start-up procedure is used that increases the reliability that the start-up will be successful using the remedial actions, such as reducing cathode airflow and turning on stack end cell heaters.

Abstract: A fuel cell power plant assembly includes an accumulator having a housing. In one example, at least one demineralizer portion is positioned to interact with fluid within the accumulator housing. This allows for warm fluid within the accumulator housing to provide heat to the demineralizer portion. In one example, the demineralizer portion is within the housing. Another example includes a separator supported within the housing of the accumulator. A disclosed example includes a conical shaped baffle as the separator. The separator separates liquid from gas and facilitates distributing fluid flow within the accumulator housing to provide increased heat exchange with the demineralizer portion within the housing.

Abstract: Embodiments are disclosed that relate to increasing radiative heat transfer in a steam reformer from an exterior shell which includes a diffusion burner to an interior reactor via angled fins coupled to the exterior shell. For example, one disclosed embodiment provides a steam reformer, comprising an exterior shell which includes a diffusion burner and angled fins, the angled fins extending away from an inner surface of the exterior shell and downward toward the diffusion burner. The steam reformer further comprises an interior reactor positioned at least partly within the exterior shell.

Abstract: A fuel cell system includes a fuel cell which has a catalyst layer therein and which receives supply of a reactive gas to generate power, and a refrigerant system which supplies a refrigerant to the fuel cell to control its temperature. A method for stopping an operation of the system is also provided. When operated in a low-temperature environment, the system cannot be restarted due to freezing in the fuel cell. When the temperature of the fuel cell during the next system start is a predetermined temperature or less, the supply of the refrigerant is stopped during the system stop, and the supply of the refrigerant is resumed after elapse of a predetermined time.

Abstract: An anode casing having a bright tin or bright tin alloy surface layer at least on an inside surface of the casing, preferably on the entire surface of the anode casing, and to an electrochemical cell containing the anode casing. Methods for preparing anode casings and electrochemical cells containing the anode casings are disclosed. In a preferred embodiment, the anode casings are plated at high current density utilizing a variable contact rack plating process, wherein portions of a clamp assembly of the device variably or alternately contact different portions of the anode casing so the entire surface of the anode casing is plated. The bright tin-plated surface is a high hydrogen-overvoltage metal that reduces gassing in cells using the casings.

Abstract: A flow control assembly for use in a fuel cell system, comprising a sensor for sensing hydrogen concentration in one of anode exhaust leaving an anode side of the fuel cell system and a gas derived from the anode exhaust, and a fuel flow control assembly for controlling the flow of fuel to the anode side of the fuel cell system based on the hydrogen concentration sensed by the sensor.

Abstract: Systems and methods for regulating fuel cell air flow, such as during low loads and/or cold temperature operation. These systems and methods may include providing a thermal management fluid, such as air, to the fuel cell stack, transferring thermal energy between the thermal management fluid and the fuel cell stack, and varying the flow rate of the thermal management fluid that comes into contact with the fuel cell stack to maintain the temperature of the fuel cell stack within an acceptable temperature range. Varying the flow rate of the thermal management fluid may include varying the overall supply rate of the thermal management fluid within the fuel cell system and/or providing an alternative flow path for the thermal management fluid such that a portion of the thermal management fluid supplied by the fuel cell system does not come into contact with the fuel cell stack.

Abstract: A method for the thermal management of a fuel cell, which method comprises: processing a fuel supply stream comprising hydrogen, steam, at least one carbon oxide and optionally methane using a methanator to produce a fuel cell supply stream comprising a controlled concentration of methane; and reforming within the fuel cell methane present in the fuel cell supply stream, wherein the way in which the methanator is operated is adjusted in response to fluctuations in the temperature of the fuel cell such that the concentration of methane in the fuel cell supply stream is controlled in order to achieve a desired level of reforming of methane within the fuel cell.

Abstract: A solid oxide fuel cell includes a core with an anode inlet, an anode outlet, a cathode inlet and a cathode outlet. A first heater is connected to the anode inlet of the core. A second heater is connected to the cathode inlet of the core. A reformer is connected to the first heater. A heat exchanger is connected to the second heater. A burner is connected to the reformer and the anode and cathode outlets of the core. A humidifier is connected to the reformer. A first gas supply is connected to the humidifier. A second gas supply is connected to the reformer. A third gas supply is connected to the burner. A fourth gas supply is connected to the heat exchanger.

Abstract: The water content estimation apparatus for a fuel cell includes an estimating unit for estimating a residual water content distribution in a reactant gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of a single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane between the anode electrode and the cathode electrode. The fuel cell system performs control based on an estimation result by the estimating unit so that the fuel cell assumes a predetermined water condition.

Abstract: A method for determining whether a fuel cell stack is overheating. The method measures the temperature of end cells in the stack using end cell temperature sensors, and calculates an average end cell temperature based on the end cell temperature measurements. The method also measures the temperature of a cooling fluid being output from the fuel cell stack. The method determines if any of the measured end cell temperatures are outlying by comparing each end cell temperature measurement to the average. The method determines that the cooling fluid outlet temperature sensor has possibly failed if the cooling fluid outlet temperature is greater than the average end cell temperature and the cooling fluid outlet temperature minus the average end cell temperature is greater than a predetermined temperature value.

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: When a vehicle mounted with a fuel cell system travels using electric power supplied from the system, a predetermined portion forming the system, such as a fuel cell, is prevented from being frozen by the relative wind. The fuel cell system is mounted on a vehicle and has the fuel cell for generating electric power by using fuel gas and oxidized gas as fuel and also has a control section for controlling the system. When the speed of the vehicle is higher than or equal to a predetermined threshold and predetermined conditions determined by physical quantities relating to power generation conditions of the fuel cell are satisfied, the control section determines that freeze prevention processing is necessary even if the fuel cell is generating electric power and performs the processing.