摘要:
The present invention relates to a skutterudite thermoelectric material for directly converting heat generated by the Seebeck effect into electricity, and provides a method of producing a Co—Sb-based filled-skutterudite sintered material having a lower thermal conductivity and thereby having a higher figure of merit. The crystal grains of a Sb-containing skutterudite compound and a metal oxide dispersed in the crystal grain boundaries are sintered to obtain the skutterudite thermoelectric sintered material. The metal oxide prevents growth of grains in the process of sintering, whereby the skutterudite compound is finely pulverized to have an average crystal grain size of 20 &mgr;m or less. As a result, the areas at the boundaries of the fine crystal grains are increased, phonon scattering is enhanced, the thermal conductivity is decreased, and the figure of merit is increased. The metal oxide is an oxide of a rare earth metal. The skutterudite compound includes a filled-skutterudite compound having a composition of LnyFexCo4−xSb12 (Ln: a rare earth metal, 0
摘要:
A piezoelectric pressure sensor includes a generally elongated sensor housing, a pressure receiving plate disposed at a first end of the sensor housing with a first surface thereof serving as a pressure receiving surface for receiving a pressure applied from outside of the sensor housing, a pressure transmission member accommodated in the sensor housing with a first end thereof held in contact with a second surface of the pressure receiving plate, and a tubular piezoelectric element accommodated in the sensor housing with a first end thereof held in contact with a second end of the pressure transmission member. A pair of electrodes are formed on the external and internal surfaces of the piezoelectric element, respectively. An external charge detection member is held in contact with the external electrode for collecting charge generated by the external electrode and is encircled by a heat-shrinkable tube, while an internal charge detection member is held in contact with the internal electrode for extracting charge therefrom. A fixing screw is threaded into the sensor housing for holding in a prestressed fashion the piezoelectric element and the pressure transmission member against the pressure receiving plate. During assemblage of the pressure sensor, the heat-shrinkable tube undergoes a thermal shrinkage upon application of heat thereto, thereby compressing the external charge detection member radially inwardly against the external electrode.
摘要:
A fuel cell separator of the present invention is provided with a reactant gas flow region (8) including a plurality of straight portions (11) and one or more turn portions (12). At least one of one or more turn portions (12) includes a gas mixing portion (12b), a gas meeting portion (12a), and a gas separating portion (12c). Second rib portions (14) are formed in the gas meeting portion (12a) and the gas separating portion (12c). The second rib portions (14) are formed such that the length of an inner second rib portion (14) is shorter than the length of an outer second rib portion (14) in a direction in which the second rib portions (14) extend. An outermost second rib portion (141) located farthest from a center rib portion (13A) is formed so as to be bent inward toward the center line (131).
摘要:
The durability of a polymer electrolyte fuel cell is very significantly improved by using a tightening pressure of about 2 to 4 kgf/cm2 of area of electrode; or a tightening pressure of about 4 to 8 kgf/cm2 of contact area between electrode and separator plate; or by selecting a value not exceeding about 1.5 mS/cm2 for the short-circuit conductivity attributed to the DC resistance component in each unit cell; or by selecting a value not exceeding about 3 mA/cm2 for the hydrogen leak current per area of electrode of each MEA. Further, in a method of manufacturing or an inspection method for a polymer electrolyte fuel cell stack, fuel cells having high durability can be efficiently manufactured by removing such MEAs or unit cells using such MEAs or such cell stacks having short-circuit conductivity values and/or hydrogen leak current values exceeding predetermined values, respectively.
摘要翻译:通过使用约2至4kgf / cm 2的电极面积的紧固压力,可以显着改善聚合物电解质燃料电池的耐久性; 或约4〜8kgf / cm 2的电极与隔离板之间的接触面积的紧固压力; 或通过选择不超过约1.5mS / cm 2的值,对于每个晶胞中的直流电阻分量导致的短路导电率; 或者通过为每个MEA的电极面积的氢泄漏电流选择不超过约3mA / cm 2的值。 此外,在聚合物电解质燃料电池堆的制造方法或检查方法中,通过使用这样的MEA或这种具有短路导电性值的电池组除去这样的MEA或单元电池,能够有效地制造具有高耐久性的燃料电池,和/ 或氢泄漏电流值分别超过预定值。
摘要:
A method of preserving a PEFC stack of the present invention is a method of preserving a PEFC stack that is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The method comprises preserving the polymer electrolyte fuel cell stack in an uninstalled state under a condition in which an oxygen concentration within the oxidizing agent passage and within the reducing agent passage is lower than an oxygen concentration in atmospheric air.
摘要:
A method of operating a fuel cell capable of suppressing degradation of a fuel cell caused by starting and stopping of the fuel cell, including carrying out a restoring operation by decreasing a voltage of the cathode following termination of the fuel cell.
摘要:
A decrease in voltage in a polymer electrolyte fuel cell comprising stack of unit cells caused by the temperature difference between the cells located at the ends and the other cells due to a differential in heat dissipation from end plates is prevented by controlling the cooling temperature of the cells closest to the end plates of the fuel cell without affecting the output voltage of the cells in the middle by not including a coolant flow channel in the conductive separator plate between at least one of the end plates and the unit cell located closest to the one of the end plates.
摘要:
A fuel cell stack of the present invention includes intermediate current collectors (52, 53) which are disposed in an intermediate portion between a pair of end portion current collectors (50, 51) and are configured to divide anode gas supply manifolds (192I, 392I) and cathode gas supply manifolds (193I, 393I), two or more sub-stacks (P, Q, R) each configured to include one or more unit cells (110, 210, 310) which are stacked between two collectors which are included in a pair of end portion current collectors (50, 51) and the intermediate current collectors (52, 53), anode gas supply inlets (172I, 272I) which are connected to anode gas supply manifolds (192I, 392I) in one of sub-stacks (P, Q, R), and cathode gas supply inlets (173I, 273I) which are connected to cathode gas supply manifolds (193I, 393I) in one of sub-stacks (P, Q, R).