Abstract: A fuel gas passage, an oxygen-containing gas passage, and a coolant passage extend through a fuel cell stack. Each of the fuel gas passage and the oxygen-containing gas passage is formed by serially connecting passages between the first through third fuel cell modules. The fuel gas flows through the fuel gas passage, and the oxygen-containing gas flows through the oxygen-containing gas passage from the first fuel cell module toward the third fuel cell module. The coolant passage is formed by serially connecting passages between the first through third fuel modules. The coolant flows through the coolant passage from the third fuel cell module toward the first fuel cell module. The direction of the flow of the coolant is opposite to the direction of the flows of the fuel gas and the oxygen-containing gas.

Abstract: A casing includes end plates and first through fourth side plates. The first and third side plates are short, and the second and fourth side plates are long. At least cross sectional areas or shapes of the first through fourth side plates are determined such that the sides of the end plates have substantially the same deflection in the stacking direction.

Abstract: A first unit cell of a fuel cell stack has a first joint body sandwiched between a first separator and a second separator. The second separator has a first metal sheet having a region where grooves and ridges alternate with each other and a second metal sheet having a region where grooves and ridges alternate with each other, and a leaf spring interposed between the first and second metal sheets. The leaf spring is held against crests of the ridges of the first and second metal sheets. The grooves of the first metal sheet face the ridges of the second metal sheet across the leaf spring, and the ridges of the first metal sheet face the grooves of the second metal sheet across the leaf spring.

Abstract: A cell assembly includes a first unit cell and a second unit cell stacked to each other. The first unit cell includes a first unified body, and the second unit cell includes a second unified body. In the cell assembly, oxidizing gas passages and fuel gas passages are provided in parallel along the first and second unit cells.

Abstract: A cell stack, in which a plurality of cell units are stacked, is accommodated in a case which has a bottom plate, a first side plate, a second side plate, and a ceiling plate. End plates are arranged at both open ends of the case. The case and the end plates are connected to one another by a hinge mechanism in which pins are engaged into through-holes of tab sections to provide a fuel cell stack.

Abstract: A heat medium passage for controlling the temperature of the electric power generation section is separated from the electric power generation section of a fuel cell including a plurality of separators and electric power generating elements alternately laminated in a lamination direction. A heat plate exchanges heat with at least one of the heat medium passage and a heat medium in the heat medium passage and is connected to the separators to provide an electrical conduction between the separators in the lamination direction. An electrical insulator is provided for insulation between the heat medium and the heat plate. Another heat medium passage may be further provided on the other side. A temperature control system for the fuel cell may include a burner for supplying the heated heat medium to the heat medium passage and may comprise first and second fluidic passages independently to selectively use the first and second fluidic passage.

Abstract: The concentration of a nitrogen gas in a circulatory supply passage connected to an anode is detected by a nitrogen concentration detector. Based on the detected concentration, the rotational speed of a pump disposed in the circulatory supply passage is controlled to adjust a hydrogen gas supplied to the anode in order to provide a desired stoichiometry for generating a target load current that is set by a target load current setting unit.

Abstract: A humidity sensor is disposed in a circulation passage as a passage of a hydrogen gas supplied to an anode of a fuel cell stack. A load current setting unit determines a level of electrical current supplied to a load. A flow rate controller controls a compressor based on the humidity detected by the humidity sensor and the load current determined by the load current setting unit to regulate a flow rate of the air supplied to a cathode of the fuel cell stack for maintaining the humidity of the hydrogen gas within a predetermined range less than 100%. The fuel cell stack generates the load current efficiently without discharging the hydrogen gas to the outside.

Abstract: A fuel cell stack (10) includes a first sub-stack (12), a second sub-stack (14), and a third sub-stack (16) disposed in the flow direction of an oxidizing gas. An intermediate plate (18a) is interposed between the first and second sub-stacks (12, 14), and an intermediate plate (18b) is interposed between the second and third sub-stacks (14, 16). In this fuel stack (10), the flow of an oxidizing gas is set such that the oxidizing gas flows in series in the direction from the first sub-stack (12) to the third sub-stack (16). Between the sub-stacks additional oxidizing gas supplies (70,74) are provided through which oxidizing gas of lower humidity than the humidity of the oxidizing gas entering the first sub-stack is supplied. This arrangement allows an efficient management of the humidity water content of the oxidizing gas with sufficient moisturizing of the solid polymer membrane whilst avoiding excessive condensation of water vapour within the stack.

Abstract: A cell assembly (10) includes a first unit cell (14) and a second unit cell (16) which are stacked to each other. The first unit cell (14) has a first unified body (18), and the second unit cell (16) has a second unified body (20). A plurality of oxidizing gas passages (46, 58) and a plurality of fuel gas passages (56, 52) are provided in the cell assembly (10). The oxidizing gas passages (46)in the first unit cell (14) and the oxidizing gas passages (58) in the second unit cell (16) are communicated in series to each other. The fuel gas passages (56) in the first unit cell (14) and the fuel gas passages (52) in the second unit cell (16) are communicated in series to each other.

Abstract: A fuel gas inlet is provided at an outer circumferential edge portion of a second separator. First fuel gas flow passage grooves for supplying a fuel gas to an anode electrode are formed on a side of a surface of the second separator. First fuel gas connecting flow passages, which make communication between the fuel gas inlet and the first fuel gas flow passage grooves, include flow passage grooves which are provided on a side of a surface, and through-holes which penetrate through the second separator to make communication with the first fuel gas flow passage grooves. Accordingly, excellent sealing performance is ensured with a simple structure, and it is possible to realize a thin-walled fuel cell.

Abstract: A fuel cell stack is formed by stacking a plurality of fuel cells. A heating mechanism is provided for heating an outermost fuel cell by external electrical energy. A power generation circuit including electric heaters corresponding to the fuel cells is provided. Further, a switching mechanism including switches for selectively connecting the fuel cells to the power generation circuit or selectively disconnecting the fuel cells from the power generation circuit is provided.

Abstract: The present invention provides a fuel stack comprising: a plurality of fuel cell units stacked together in a direction of stacking each of which comprises an electrolyte element, a pair of electrodes holding the electrolyte element therebetween, and a pair of separators holding the electrodes therebetween; a pair of terminal plates each of which is disposed outside an end fuel cell unit located at an end of the stacked fuel cell units; and a terminal element extending outwardly in the direction of stacking from the outside surface of at least one of the terminal plates; wherein the location from which the terminal element extends is located within an area on the terminal plate, corresponding to an area in a passage for an oxidizing gas formed in the end fuel cell unit disposed adjacent to the terminal element where the partial pressure of water vapor is lower than the saturated water vapor pressure.

Abstract: A fuel cell includes an electrolyte electrode assembly and a pair of first and second separators. First through fourth oxygen-containing gas holes, first through fourth coolant holes, and first through fourth fuel gas holes extend through the fuel cell. The first through fourth oxygen-containing gas holes are selectively used as an oxygen-containing gas supply port or an oxygen-containing gas discharge port to cause an oxygen-containing gas to flow circularly along an electrode surface in an oxygen-containing gas flow field.

Abstract: A cell assembly is formed by stacking a first fuel cell and a second fuel cell together. The first fuel cell has a first membrane electrode assembly, and the second fuel cell has a second membrane electrode assembly. In the cell assembly, oxygen-containing gas flow fields of the first and second separators are connected in series, and fuel gas flow fields of the first and second separators are connected in series. Coolant flow fields are formed on opposite sides of the cell assembly, respectively, for supplying a coolant straight in one direction through the coolant flow fields.

Abstract: A fuel cell includes an electrolyte electrode assembly and a pair of first and second separators. First through fourth oxygen-containing gas holes, first through fourth coolant holes, and first through fourth fuel gas holes extend through the fuel cell. The first through fourth oxygen-containing gas holes are selectively used as oxygen-containing gas supply ports or oxygen-containing gas discharge ports to change the flow direction of an oxygen-containing gas in an oxygen-containing gas flow field continuously.

Abstract: A fuel gas inlet is provided at an outer circumferential edge portion of a second separator. First fuel gas flow passage grooves for supplying a fuel gas to an anode electrode are formed on a side of a surface of the second separator. First fuel gas connecting flow passages, which make communication between the fuel gas inlet and the first fuel gas flow passage grooves, include flow passage lo grooves which are provided on a side of a surface, and through-holes which penetrate through the second separator to make communication with the first fuel gas flow passage grooves. Accordingly, excellent sealing performance is ensured with a simple structure, and it is possible to realize a thin-walled fuel cell.

Abstract: An upper wing surface of a laminar-flow airfoil includes: a front profile portion which has a positive curvature radius, and which is provided to extend from a leading edge to a largest-thickness point located at a position corresponding to 38% of a wing chord length. The front profile portion forms a laminar-flow boundary layer. A central profile portion has a positive curvature radius and is provided to extend from the largest-thickness point to the vicinity of a position corresponding to 90% of the wing chord length at which a value obtained by dividing a thicknesswise difference between the position and the largest-thickness point by a distance in a direction of the wing chord from the largest-thickness point is equal to or smaller than 0.12.

Abstract: A fuel cell stack comprises a power-generating cell and a cooling cell which are stacked, an insulating means for electrically insulating the cooling medium supplied into the cooling cell from the power-generating cell, and a conducting means for electrically connecting the power-generating cells arranged with the cooling cell interposed therebetween to one another. Accordingly, the earth fault and the liquid junction, which would be otherwise caused by cooling medium, is reliably avoided with a simple structure, making it possible to maintain desired power generation performance.

Abstract: A fuel gas passage, an oxygen-containing gas passage, and a coolant passage extend through a fuel cell stack. Each of the fuel gas passage and the oxygen-containing gas passage is formed by serially connecting passages between the first through third fuel cell modules. The fuel gas flows through the fuel gas passage, and the oxygen-containing gas flows through the oxygen-containing gas passage from the first fuel cell module toward the third fuel cell module. The coolant passage is formed by serially connecting passages between the first through third fuel modules. The coolant flows through the coolant passage from the third fuel cell module toward the first fuel cell module. The direction of the flow of the coolant is opposite to the direction of the flows of the fuel gas and the oxygen-containing gas.