Abstract: An electrochemical cell includes an anode, a cathode including a gas diffusion electrode and having first and second surfaces, an inlet for gaseous oxidant that is in contact with the first surface of the cathode, and a liquid electrolyte. Water generated at the cathode may be transported by osmosis into the liquid electrolyte. The fuel cell may produce a current density of 200 mA/cm2 without cathode flooding.

Abstract: A waterless power generator, particularly a waterless electrical power generator and a passively controlled process for producing electricity with a fuel cell using stoichiometric amounts of a solid hydrogen fuel and byproduct water vapor produced by the fuel cell to generate hydrogen gas. A fuel cell reaction of hydrogen and oxygen produces electrical energy as well as by-product water which diffuses back into the power generator as water vapor to react with the hydrogen fuel, producing more hydrogen gas. This generated hydrogen gas is then used as a fuel which allows the fuel cell to generate additional electrical power and additional water. The process runs without any attached water source or water supply other than the water which is produced by the fuel cells themselves.

Abstract: Disclosed herein is a hydrogen storage material comprising a metal hydride and an organic hydrogen carrier. Also disclosed herein is a hydrogen storage/fuel cell system which employs the hydrogen storage material.

Abstract: A power generator has a hydrogen flow path through which moisture is induced to flow to a hydrogen-containing fuel that reacts with the moisture to produce hydrogen. The moisture passes to the hydrogen flow path through a water exchange membrane from a water vapor flow path. A fuel cell between the hydrogen flow path and the water vapor flow path reacts with the hydrogen in the hydrogen flow path to produce electricity, and to also principally produce the moisture in the water vapor flow path.

Abstract: A fuel cell system includes: a fuel cell to which a reaction gas is supplied to generate electricity; a circulating system which returns unreacted reaction gas discharged from the fuel cell to an upstream of the fuel cell to thereby circulate the unreacted reaction gas; a discharge device which discharges the unreacted reaction gas from the circulating system; a first pressure detector which detects a pressure at a downstream of the discharge device; and a controller which controls an amount of discharged gas to be discharged from the circulating system by the discharge device, based on the pressure detected by the first pressure detector.

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: A carbon-based energy system including an apparatus for generating electricity and byproduct CO2, a photosynthesis bioreactor that converts CO2, and a CO2 storage unit. In one embodiment, the energy system includes a direct carbon fuel cell (DCFC), a photosynthetic bioreactor, and a thermoacoustic cooler. Also provided is a method for reducing CO2 emission in energy systems achieved by coupling a photosynthetic bioreactor and a CO2 storage system with an energy system wherein the CO2 produced by the energy system is converted to biomass during light hours and is stored during dark hours.

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: By providing a coloring agent, which is brought in contact with the liquid fuel leaked from an outer peripheral portion of the liquid fuel holding section that is configured to hold the liquid fuel and by which the contact portion is changed in color, in at least part of the outer peripheral portion, the leakage of the liquid fuel from the liquid fuel holding section can be visually detected swiftly and easily without providing any special detection device.

Abstract: Hydrogen-producing fuel cell systems with load-responsive feedstock delivery systems, and methods for regulating the delivery of feedstock to the hydrogen-producing region of a fuel cell system. The fuel cell systems include a control system that is adapted to monitor and selectively regulate the rate at which the feedstock is delivered to a hydrogen-producing region of a hydrogen generation assembly. The control systems, and corresponding methods, include feed-forward and feedback control portions that cooperatively regulate the rate at which the feed stream is delivered to the hydrogen generation assembly responsive at least in part, if not completely, to the fuel cell stack's demand for hydrogen gas and the rate at which the produced hydrogen gas is consumed by the fuel cell stack.

Abstract: According to one embodiment of the present invention, a fuel cell life counter is configured to determine membrane degradation using fuel cell cycling data and S-N curve data for the membrane. According to another embodiment of the present invention, a method of managing remaining fuel cell life is provided where variables like membrane dehydration rate, water content, temperature, and heating/cooling rate are controlled as a function of the remaining life of the fuel cell. Additional embodiments are provided where fuel cell life counters and methods of managing remaining life are independent of S-N curve data and the use of fatigue life contour plots.

Abstract: An oxidizer assembly provided with a housing having a plurality of inlets each for receiving a different gas and a plurality of outlets each corresponding to a different one of the inlets and outputting gas resulting from the gas received from its corresponding inlet. A catalyst assembly able to support gas flow therethrough is disposed within the housing and includes a catalyst able to oxidize carbon monoxide gas and to be regenerated. The catalyst assembly is further adapted to be movable such that successive parts of the assembly are able to be brought repeatedly in communication with a first inlet and its corresponding first outlet and then a second inlet and its corresponding second outlet of the housing.

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 fuel cell capable of being thinned while maintaining a stable electric power supply is provided. A fuel cell includes a power generation section, a fuel tank, a fuel supply section (pump), and a fuel vaporization section. The power generation section has a structure in which a combined body is sandwiched between a cell plate and a cell plate. The combined body has a structure in which an anode electrode and a cathode electrode are oppositely arranged with an electrolyte film in between. In particular, the fuel supply section and the fuel vaporization section are integrally provided, and are connected by a nozzle section buried therein. A fuel contained in the fuel tank is pumped by the fuel supply section according to the state of the power generation section, and then is vaporized by the fuel vaporization section, and is supplied to the power generation section side.

Abstract: A nonaqueous electrolytic cell manufacturing method is characterized in that a nonaqueous electrolyte containing vinylene carbonate is used, a coating on the surface of the negative electrode is formed at the initial charging/discharging in such a way by lowering the negative electrode potential to less than 0.4 V with relative to the lithium potential, wherein the nonaqueous electrolytic cell comprises a nonaqueous electrolyte containing an electrolytic salt and a nonaqueous solvent, a positive electrode, and a negative electrode containing a negative electrode material into/from which lithium ions are inserted/desorbed at a potential higher than the lithium potential by 1.2 V. The nonaqueous electrolytic cell is used in a range of negative electrode potential nobler than the lithium potential by 0.8 V.

Abstract: Embodiments of the present invention relate generally to redox flow batteries and, more specifically, to flow batteries that employ electron-ferrying redox compounds made from polyoxometalates (“POMs”). Embodiments of the present invention employ flow-battery technology that combines the fast electrochemical reaction of a battery with the fuel flexibility of a fuel cell to meet next-generation energy needs of a variety of power applications, including portable electronics used in military and commercial applications and large power modules that provide 550 W or more. To obtain a high-power-density stack, a reduced form of liquid POM is fed to the stack of cells, in certain embodiments of the present invention, where the reduced form of liquid POM is efficiently oxidized into liquid products at the anodes. Air is fed and reduced at the cathodes, generating water as a byproduct.

Abstract: A method of shutting down a hydrogen generation apparatus for limiting degradation in a catalyst due to dew condensation at the time of shutdown is provided. The method of shutting down the hydrogen generation apparatus comprising, a combustor which supplies heat necessary to a reforming device, a first air supplier which supplies air to the combustor, a combustion exhaust gas path formed such that the combustion exhaust gas produced in the combustor makes heat exchange with the reforming device and then with a CO reducing device, and a controller which operates the first air supplier so that the temperature of the gas in the CO reducing device does not become equal to or lower than a dew point after shutdown of the combustion operation of the combustor and before a start of a purging operation to purge the interiors of the reforming device and the CO reducing device with a replacement gas.

Abstract: A system and method for reducing concentrations of reactants in gases flowing through an exhaust system are disclosed. Briefly described, one embodiment comprises creating a turbulent flow of gases along a periphery region of an exhaust pipe, the turbulent flow created by the gases transported over a wire mesh residing in the periphery region; and mixing the gases in the periphery region with a reactant gas being transported in a flow-through region, the mixing caused by the turbulent flow of gases, such that concentration of the reactant gas is reduced as the reactant gas is transported through the exhaust system.

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 system and method for reducing cathode carbon corrosion during start-up of a fuel cell stack. If a long enough period of time has gone by since the last system shutdown, then both the anode side and the cathode side of the stack will be filled with air. If the system includes split sub-stacks, then a start-up sequence uses a fast hydrogen purge through each sub-stack separately so as to minimize the time of the hydrogen/air front flowing through the anode side of the stacks. The start-up sequence then employs a slow hydrogen purge through the sub-stacks at the same time. If the time from the last shutdown is short enough where a significant amount of hydrogen still exists in the cathode side and the anode side of the sub-stacks, then the fast hydrogen purge can be eliminated, and the start-up sequence proceeds directly to the slow hydrogen purge.

Abstract: The present invention relates to a passive dilution unit which has a throughflow channel for fuel, the throughflow channel having at least one window in which a membrane provided with a catalyst is fitted. By means of diffusive processes, for example atmospheric oxygen can penetrate through the membrane to the fuel flow and cause a reaction by means of oxidative processes imparted by the catalyst, in which reaction the fuel is oxidised into water. The thereby resulting water is retained directly in the fuel flow and thereby directly dilutes the fuel.

Abstract: An integrated fuel processor apparatus and enclosure for converting hydrocarbon fuel to a hydrogen rich gas. The integrated apparatus includes a fuel processor for producing a hydrogen-rich reformate that contains water and a combustible gas component. The fuel processor is enclosed in a gas impermeable enclosure that has a collection vessel for receiving water separated from the reformate stream. Methods for manufacturing an apparatus for separating water from a reformate stream for safe disposal and methods for separating water from a reformate stream for safe disposal are disclosed.

Abstract: A method for operating a direct methanol fuel cell is provided. The fuel cell includes a fuel cell main body having a fuel electrode and an air electrode disposed in opposing positions on either side of an electrolyte film. In this method, an aqueous methanol solution is supplied directly to the fuel electrode. A quantity of the aqueous methanol solution supplied is controlled in accordance with an electric current value drawn from the fuel cell main body so as to minimize a quantity of unused methanol within a discharge fluid discharged from the fuel electrode.

Abstract: To provide a fuel cell that can perform efficient power generation through a simple fuel supply. There is provided a fuel cell that generates electricity through progress of an oxidation-reduction reaction using an enzyme as a catalyst, the fuel cell including at least a fuel-vaporizing layer formed through vaporization of a fuel; an anode to which a vaporized fuel is supplied from the fuel-vaporizing layer; and a cathode connected to the anode in a state in which protons can be conducted. In the fuel cell, since a fuel is supplied to an electrode in a vaporized state, a vaporized fuel is supplied to an inner portion of the electrode and a reaction sufficiently proceeds at the inner surface of the electrode, which can achieve high output due to efficient power generation.

Abstract: An electrochemical cell, and a method of producing an electrochemical cell are provided. The method includes a step in which a counter electrode film and a mold film are crimped. A sol-gel precursor is inserted into a pore in the mold film provided on the counter electrode film. The sol-gel precursor is cooled to form a semi-hardened gel. The mold film is peeled off from the counter electrode film. The semi-hardened gel is cooled to form a gel electrolyte film. The sealing film is provided on the counter film, with the gel electrolyte film being fitted in the pore of the sealing film. A working electrode film is crimped on the sealing film. The stacked films are thermocompression bonded, and a single electrochemical cell is produced by cutting.

Abstract: A fuel cell system includes a fuel cell stack and a PEM stack for providing power to the system in a start up or shut down operating mode and hydrogen to the fuel cell stack in a steady state operating mode.

Abstract: A fuel cell power generation system which adjusts the amount of fuel, in a fuel cell power generation apparatus, into a predefined range is provided. A fuel cell system includes a fuel cell power generation apparatus, a control means which has the fuel cell power generation apparatus output a preset electric power value, and a power supply unit which charges and supplies an electric power to an external. The control means changes the electric power value outputted from the fuel cell power generation apparatus, based on the status of liquid fuel detected by a fuel state detecting means.

Abstract: A hydrogen fuel cell system (100) for charging a battery (116) of an electric vehicle, includes at least one tank (102) for storing hydrogen under pressure. A combined heat exchanger and air engine (104) expands the pressurized hydrogen and converts the expanding hydrogen into mechanical energy. A plurality of fuel cells (106) receive the expanded hydrogen for supplying heat to the heat exchanger and air engine (104) and supplying a first current for charging the battery (116). A generator (108) generates a multi-phase voltage in response to the mechanical energy. A electrical power converter (110) responsive to the multi-phase voltage provides a second current for charging the battery (116).

Abstract: A method of generating steam by heating water in a steam generator comprising a plurality of steam generating channels, wherein water is supplied at a constant rate to each steam generating channel through respective water supply lines, and wherein a sufficient pressure drop is provided across each water supply line in order to prevent flow reversal in the plurality of steam generating channels.

Abstract: A reaction vessel that integrates and balances an endothermic process with at least one exothermic process of the fuel cell system. Preferably the exothermic process is conducted in stages to provide more uniform and/or controllable heat generation and exchange, and to produce a uniform and/or controllable temperature profile in the endothermic reaction process. The invention allows for the elimination of the working fluid loop of prior art systems that had unsatisfactory response times at startup, and during transient conditions, and also added to the overall mass and volume of the fuel cell system.

Abstract: A fuel cell arrangement including a plurality of fuel cells, each fuel cell including an electrolyte membrane disposed between an anode and a cathode, first and second flow field plates adjacent the anode and cathode, respectively; a fuel cell health management (FCHM) device; a plurality of plate members interposed between each of the fuel cells and being made of an electrically conductive metallic material and disposed between the first and second flow field plates of adjacent fuel cells to connect the fuel cells in series, and having an electrically conductive tab. The tab of each of the plate members being electrically connected to the FCHM to conduct current provided by the FCHM to provide a substantially uniform voltage over each electrically of the plate members to rejuvenate each fuel cell, to monitor each fuel cell, and to control each fuel cell, and having a heat sink for dissipating heat.

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: A fuel cell discharge-gas processing device that dilutes anode off-gas discharged from a fuel cell anode by mixing the anode off-gas with a diluent gas so as to produce a diluted gas and then discharges mixture of the anode off-gas and the diluent gas, includes: a dilution container; an anode off-gas introduction path; a diluent gas path through; a diluent gas emission hole; a mixed gas discharge hole; at least one partition panel; and a communication gas path, wherein the anode off-gas emission hole is provided so as to emit anode off-gas toward the partition panel.

Abstract: A method for forming a reinforced rigid anode monolith and fuel and product of such method.

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: In various aspects, provided are methods for: (a) improving oxygen incorporation in a solid oxide layer less than about 1000 nm thick; (b) extending the on-set of mixed conduction in a solid oxide layer less than about 1000 nm thick; (c) modulating the electrical conductivity of oxide ion conducting layer less than about 1000 nm thick; (d) decreasing the conductivity of an oxide ion conducting layer less than about 1000 nm thick; (e) improving the performance of a solid oxide fuel cell; and (f) improving the performance of a gas separation device. In various embodiments, the methods comprise exposing oxygen to light having one or more wavelengths in the range between about 100 nm to about 365 nm and contacting the layer with the oxygen so exposed. In various embodiments, the methods provide the potential for tailoring the surface catalytic activity of oxygen-ion and mixed conductors used in various solid-state devices.

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 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 having a temperature above 200 C, lowering a temperature of the fuel exhaust stream to 200 C or less, separating the fuel exhaust stream into a first separated fuel exhaust stream and a second separated fuel exhaust stream, and recycling the first separated fuel exhaust stream into the fuel inlet stream.

Abstract: The invention relates to an aircraft, in particular to an airplane, having at least one fuel cell, having at least one supply line which connects the fuel cell to a fuel supply, having at least one outlet line by means of which fuel supplied by the supply line and not consumed in the fuel cell is drained off and having means for the influencing of the fuel flow through the fuel cell as well as having means for the influencing of the fuel flow through the fuel cell, with the means for the influencing of the fuel flow having a pressure regulator located in the at least one supply line and a restrictor member located in the at least one outlet line, with the pressure regulator regulating the pressure of the fuel supply to the operating pressure of the fuel cell and with the restrictor member reducing the flow of the fuel flowing through the outlet line.

Abstract: The invention relates to direct conversion of coal into electricity in a high temperature electrochemical generator in a single step process. This novel concept promises nearly doubling the conversion efficiency of conventional coal-fired processes and offering near-zero emissions. The improved efficiency would mean that nearly half as much coal is mined and transported to the power plant, and half the greenhouse gases and other pollutants such as sulfur, mercury and dioxins are produced. It also offers several crucial distinctions from conventional coal-burning processes. Since the process does not involve the combustion of coal in air, it does not involve nitrogen and hence generates practically no NOx. Accordingly, there is also no latent heat lost to nitrogen. In this process, the oxygen necessary to oxidize coal is supplied through an ion selective ceramic membrane electrolyte.

Abstract: It is an object of the present invention to provide a fuel cell system that is capable of sensing unintended gas leakage from a discharge control means based on odor. A fuel cell system is provided with a bypass passage 32 connecting a fuel offgas passage 30 at inlet of a odorant removal unit 40 to the fuel offgas passage 30 in the vicinity of outlet of the odorant removal unit 40, and the fuel cell system facilitates the removal of odor from the discharged fuel offgas, by closing a bypass valve 33 in conjunction with opening a purge valve 31, and suppresses the removal of odor, by opening the bypass valve 33 in conjunction with stop of discharge of fuel offgas caused by closing the purge valve 31.

Abstract: A fuel cell, comprising an electrolyte body and, embedded within it, at least two separate electrodes capable of conducting electrons; the electrodes being sufficiently porous to allow gas flow through them; one electrode being an electrically negative anode and the other electrode being an electrically positive cathode, and the electrolyte body being capable of carrying charged particles between the anode and cathode; the anode and cathode being electrically connected to form an electrical circuit.

Abstract: The present invention discloses methods and devices for humidifying the proton exchange membranes of fuel cells with water obtained from the exhaust of the fuel cells. Humidifying methods include the following steps: cooling the hot and humid exhaust of the fuel cell to condense the water in the exhaust with the intake gas for the fuel cell; separating the water from the rest of the exhaust, and, delivering the water to the intake gas of the fuel cell. Humidifying devices include an outer shell containing a rotating inner shell. The inside of the inner shell forms a chamber where the exhaust is collected and cooled, and water is condensed and separated by the rotation of the inner shell. Openings on the inner shell allow the condensed water to pass through to one or more chambers containing the intake gas. The chambers are formed by the inside of the outer shell and the outside of the inner shell.

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: Hydrogen is stored in materials that absorb and desorb hydrogen with temperature dependent rates. A housing is provided that allows for the storage of one or more types of hydrogen-storage materials in close thermal proximity to a fuel cell stack. This arrangement, which includes alternating fuel cell stack and hydrogen-storage units, allows for close thermal matching of the hydrogen storage material and the fuel cell stack. Also, the present invention allows for tailoring of the hydrogen delivery by mixing different materials in one unit. Thermal insulation alternatively allows for a highly efficient unit. Individual power modules including one fuel cell stack surrounded by a pair of hydrogen-storage units allows for distribution of power throughout a vehicle or other electric power consuming devices.

Abstract: A fuel cell system is provided which includes a fuel cell to which fuel gas and oxidizing gas are supplied to generate electricity, a purge valve which purges fuel gas discharged from the fuel cell, a dilutor which mixes the purged fuel gas with the oxidizing gas and purges the purged fuel gas mixed with the oxidizing gas into the atmosphere, and an ECU which stops supply of the oxidizing gas to the fuel cell so as to cause an idle stop and determines whether to permit the idle stop depending on a concentration of the fuel gas in the dilutor.

Abstract: A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

Abstract: The invention relates to a method and a device for operating a fuel cell system (1) having a recirculation blower (11) disposed in a fuel circuit of the fuel cell system (1) by means of which the fuel (BS) exiting the fuel cell system (1) on the anode side is resupplied, said blower being driven by an air-driven drive turbine (12), wherein the air-driven drive turbine (12) is impacted by compressed air (vL).

Abstract: A fuel cell system that employs surge prevention by electronically mapping the compressor for discharge pressure versus mass airflow. In one embodiment, the fuel cell system employs a mass flow meter that measures the airflow to the compressor. A controller receives a signal from the mass flow meter indicative of the flow rate of the charge airflow to the compressor, and determines the outlet pressure and temperature of the compressor from the compressor speed and the measured airflow. This gives the compressor map location at which the compressor is operating. In another embodiment, the fuel cell system employs a pressure sensor that measures the output pressure of the compressor, and provides a pressure signal to the controller. The controller determines the mass airflow to the compressor to determine the compressor map location.

Abstract: A direct methanol fuel cell system includes a fuel cell main body including at least one membrane-electrode assembly having an electrolyte membrane, and an anode and a cathode positioned on opposite sides of the electrolyte membrane; a fuel-supplying unit feeding a mixing tank with high concentration fuel; the mixing tank mixing and storing the fuel fed from the fuel-supplying unit and an outlet stream discharged from the fuel cell main body; a fuel feeder supplying mixed fuel stored in the mixing tank to the fuel cell main body; and a controller controlling the fuel-supplying unit to stop operating in response to a stop request signal, and controlling the fuel feeder to operate to circulate the mixed fuel via the anode of the fuel cell main body until a fuel concentration of the mixed fuel is less than or equal to a reference concentration.