Abstract: A fuel cell is of a simple structure for preventing a partial temperature difference from being developed in a fuel cell structural body, and maintaining an effective operative area and performance. The fuel cell 10 includes a plurality of fuel cells 20 each sandwiched between separators 40, and has circulatory passages 29a, 29b defined therein for circulating cooling water, which has been used to cool the fuel cells 20, along opposite sides of electric generation sections 28 of the fuel cells 20.

Abstract: Disclosed is a fuel cell stack comprising fuel cell units and first and second separators which are alternately stacked with each other. Wedge members are integrally inserted, over the plurality of fuel cell units, into communication holes of a fuel gas supply passage, an oxygen-containing gas supply passage, and a cooling water supply passage, as well as a fuel gas discharge passage, an oxygen-containing gas discharge passage, and a cooling water discharge passage. A fluid is uniformly delivered to each of the fuel cell units by the aid of the wedge members. Accordingly, the fluid of any one of a fuel gas, an oxygen-containing gas, and a cooling medium is uniformly delivered to each of the fuel cell units. Further, it is possible to simplify the arrangement of the fuel cell stack.

Abstract: A fuel cell system comprises a medium-circulating passage for supplying, in a circulating manner, a temperature-adjusting medium to a fuel cell stack, and first and second temperature sensors for detecting medium temperatures at a temperature-adjusting medium inlet and a temperature-adjusting medium outlet. The medium-circulating passage is provided with a pump for circulating the medium, a heater for heating the medium, a radiator for cooling the medium, a bypass passage for bypassing the radiator, and first through third opening/closing valves for selectively supplying the temperature-adjusting medium to the radiator and the bypass passage.

Abstract: A method of operating a phosphoric acid fuel cell is provided, in which the phosphoric acid fuel cell effects power generation at a high output. A power-generating cell is provided with an electrolyte layer comprising a matrix composed of basic polymer impregnated with acidic liquid electrolyte such as phosphoric acid. The phosphoric acid fuel cell has a fuel cell stack comprising a single unit of the power-generating cell or a predetermined number of the power-generating cells electrically connected in series to one another. When the phosphoric acid fuel cell is operated, the supply pressures of the oxygen-containing gas and the hydrogen-containing gas are set so that the pressure on a cathode electrode of the power-generating cell is higher than that of an anode electrode.

Abstract: A fuel cell is of a simple structure for preventing a partial temperature difference from being developed in a fuel cell structural body, and maintaining an effective operative area and performance.

Abstract: A fuel cell system comprises a fuel cell stack including stacked power-generating cells, a cooling medium-circulating passage for supplying a cooling medium to the fuel cell stack in a circulating manner to cool the power-generating cells, and a heat exchange means arranged for the cooling medium-circulating passage, for performing a heat exchange treatment for the cooling medium used to cool the power-generating cells, wherein the operation temperature of the fuel cell stack is set to be within a range of 100° C. to 210° C. Accordingly, it is possible to improve durability of the fuel cell system in the high output operation and to easily miniaturize the fuel cell system.

Abstract: Disclosed is a fuel cell stack comprising a fuel cell unit and separators which are stacked with each other. The separator is provided with a cooling medium supply port corresponding to a central portion of an electrode power-generating section and a cooling medium discharge port corresponding to an outer circumferential portion of the electrode power-generating section. The cooling medium supply port communicates with the cooling medium discharge port via a cooling medium flow passage having a spiral configuration. Accordingly, the entire fuel cell unit can be uniformly cooled, and the power-generating function can be effectively improved.

Abstract: First gas flow passage grooves communicating with a fuel gas inlet and second gas flow passage grooves communicating with a fuel gas outlet are provided on a surface of a first separator. First and second united sections are provided at merged portions of the first gas flow passage grooves and the second gas flow passage grooves. Accordingly, the number of gas flow passage grooves is throttled from the side of the fuel gas inlet to the side of the fuel gas outlet. The turbulence is allowed to occur at the throttled portion to make it possible to improve the gas diffusion performance.

Abstract: A fuel gas and an oxygen containing gas are supplied downwardly through different passages into a first manifold plate 42, a first surface pressure generating plate 44, a separator body 48, a second surface pressure generating plate 46, a second manifold plate 50, a first gasket 30, a solid polymer electrolyte membrane 22, and a second gasket 32, into which cooling water is supplied upwardly. The cooling water rises upwardly in the separator body 48 to reduce a temperature distribution in a fuel cell 20.

Abstract: A fuel cell is of a simple structure for preventing A partial temperature difference from being developed in a fuel cell structural body, and maintaining an effective operative area and performance. The fuel cell 10 includes a plurality of fuel cells 20 each sandwiched between separators 40, and has circulatory passages 29a, 29b defined therein for circulating cooling water, which has been used to cool the fuel cells 20, along opposite outer sides of electric generation sections 28 of the fuel cells 20.

Abstract: A fuel cell stack comprises first and second separators for holding a fuel cell unit therebetween. The first separator has a fuel gas flow passage and the second separator has an oxygen-containing gas flow passage. The gas flow passages are formed by grooves with the number of grooves decreasing from the inlet to the outlet. In one embodiment, the gas flow passage comprises twelve individual first gas flow passage grooves which communicate with an inlet hole on a gas inlet side, six individual second gas flow passage grooves which communicate with the first gas flow passage grooves, and three individual third gas flow passage grooves which communicate with the second gas flow passage grooves. The third gas flow passage grooves communicate with an outlet hole on a gas outlet side.

Abstract: A fuel gas supply device is equipped with a reformer for conducting steam reforming of methanol which is supplied from a methanol tank, and a hydrogen gas supply means for supplying hydrogen gas only, which is contained in the fuel gas derived from the reformer, to a fuel cell. By passing the fuel gas through a hydrogen permeable membrane or a pressure-swing adsorption device, a fuel gas in which any unreacted methanol is reliably removed therefrom can be supplied to the fuel cell. According to further embodiments, unreacted methanol is caused to positively react on a fuel electrode side of a fuel cell stack, so as to remove excess amounts of unreacted methanol from a fuel chamber. The method can further include a step of controlling the humidity of the fuel gas, by either removal or supply of moisture, before the fuel gas is supplied to the fuel cell.

Abstract: A fuel gas and oxygen containing gas are supplied downwardly through different passages into a first manifold plate 42, a first surface pressure generating plate 44, a separator body 48, a second surface pressure generating plate 46, a second manifold plate 50, a first gasket 30, a solid polymer electrolyte membrane 22, and a second gasket 32, into which cooling water is supplied upwardly. The cooling water rises upwardly in the separator body 48 to reduce a temperature distribution in a fuel cell 20.

Abstract: A fuel cell unit in which a hydrogen-side (anode) electrode and an air-side (cathode) electrode are disposed in facing relation to each other with an electrolyte membrane interposed therebetween, and wherein a separator is provided for supporting said fuel cell structure interposed therebetween. The separator has, independently disposed therein, a first cooling passage through which a first cooling medium, generally composed of water, is introduced for cooling the hydrogen-side electrode, and a second cooling passage through which a second cooling medium having a melting point below that of water is introduced for cooling the air-side electrode. Accordingly, a melting operation for the first cooling medium can be easily and swiftly carried out, while the fuel cell unit itself remains simple in structure.

Abstract: A gas humidifying device for use with a fuel cell in which water permeable membranes are provided with fuel gas passages and oxygen-containing gas passages formed on one side of the water permeable membranes, and wherein humidifying water passages are formed on the other side thereof. Medium supply passages are provided independently from, yet in proximity to the water passages, for supplying a medium having a melting point lower than that of water. Accordingly, a melting operation for melting the water in the interior of the humidifier can be easily and swiftly carried out, while the device remains simple in structure.

Abstract: A fuel cell system has a fuel cell assembly and an oxygen-containing gas supply. The oxygen-containing gas supply has a passage for introducing atmospheric air, and includes a catalytic converter for selectively oxidizing carbon monoxide contained in the air introduced into the passage, an air compressor, and an intercooler. The catalytic converter, the air compressor, and the intercooler are successively disposed in the passage. The air from which carbon monoxide has been removed by the catalytic converter is supplied as an oxidizing gas to the fuel cell assembly.

Abstract: A fuel cell system has a reformer, a water tank for supplying water to humidify a hydrogen gas and an oxidizing gas which has been reformed by the reformer, a fuel cell for being supplied with the humidified hydrogen gas, and first and second gas-liquid separators for separating substances discharged from the fuel cell into gases and water, and supplying the separated water to the water tank. The fuel cell system needs no water supply from an external source and can continuously supply the water from the water tank to the fuel cell.

Abstract: The present invention makes it possible to remove an organic solvent in an electrode paste and fix an ion-conductive component while maintaining a desired moisture content. Specifically, a sheet of carbon paper applied with the electrode paste is horizontally held in a tank which comprises a drying apparatus. Water in the tank is brought to the boil by the aid of a first heater. Accordingly, the organic solvent in the electrode paste is removed, and the ion-conductive component is fixed, while forcedly humidifying the carbon paper and the electrode paste with steam.

Abstract: A fuel cell stack having unit cells and separators, in which each unit cell comprises a solid polymer electrolyte membrane having a pair of electrode catalysts attached on both surfaces, and a pair of collectors, each made of a rigid body, being in contact with respective electrode catalysts, and each of the separators comprises a pair of pressure generating plates defining therebetween a pressure chamber to which a pressurized fluid is introduced, the pressure generating plates being deformed by the pressurized fluid and pressed against the adjacent respective collectors.

Abstract: A direct methanol type fuel cell comprises at least one fuel cell unit including an anode and a cathode and a plurality of separators. Each of the separators comprises an aqueous methanol solution flow-adjusting plate having grooves formed in parallel to a direction of gravity, and an oxygen containing gas flow-adjusting plate having grooves formed. A methanol tank and a water tank are connected to a supply passage through pumps respectively. The supply passage communicates through a passage to the aqueous methanol solution flow-adjusting plate. The aqueous methanol solution flow-adjusting plate is formed of a porous conductive material. Therefore, the aqueous methanol solution can be stably supplied at a uniform concentration to the entire operating surface of the anode.