摘要:
A textured surface is formed on at least one of a fuel cell mounting plate or fuel cell subassembly to define a joint spacing between these two components. In a preferred embodiment, the textured surface comprises a plurality of dimples coined or otherwise formed in the metal mounting plate. The joint spacing improves the manufacturing and assembly process of the fuel cell cassettes through precise application and control of the brazing process which improves the braze joint strength while reducing material cost.
摘要:
An electrical interconnect for a solid-oxide fuel cell stack assembly, including a novel sintering paste and an improved manufacturing process for an anode and cathode electrical contacts is disclosed. On the anode side, the paste contains a metallic oxide such as NiO, and an amount of sacrificial pore-forming particles, such as carbon particles or polymer spheres, which are vaporized during sintering of the paste, resulting in a very porous connection having good electrical conductivity and good adhesion. A preferred level of pore-former in the paste is about 40 volume percent. On the cathode side, the paste contains a noble metal such as for example, gold, platinum, palladium or rhodium, and an amount of the sacrificial pore-forming particles. The paste may be applied to the surfaces in a grid pattern or, because the resulting contact is porous after sintering, it may be applied as a continuous layer.
摘要:
A modular fuel cell cassette for use in assembling a fuel cell stack comprising a metal separator plate and a metal cell-mounting plate joined at their edges to form a hollow cassette. A fuel cell subassembly is attached to the mounting plate and extends through an opening in the mounting plate. The plates include openings to form chimney manifolds for supply and exhaust of fuel gas to the anode and air to the cathode. A conductive interconnect element extends from the fuel cell subassembly to make contact with the next cassette in a stack. The anode openings in the mounting plate and separator plate are separated by spacer rings such that the cassette is incompressible. A fuel cell stack comprises a plurality of cassettes, the mounting plate of one cassette being attached to, and insulated from, the separator plate of the next-adjacent cassette by a dielectric seal surrounding the interconnect.
摘要:
A fuel cell module having four sheet metal parts stamped from flat stock. The parts do not require any forming operations such as folding or dishing. Each part may have a different thickness to suit its function. The first part is a cell mounting frame for receiving and supporting a PEN fuel cell element. The second part is a cathode spacer, the thickness of the spacer determining the height of the cathode air flow field. The third part is an anode spacer, the thickness of spacer determining the height of the anode fuel flow field. The fourth part is a separator plate for separating the anode gas flow in one cell from the cathode air flow in an adjacent cell in a fuel cell stack. The four plates are joined by welding or brazing and may be assembled in any order or combination which suits the assembly process. Any desired number of modules may be stacked together to form a fuel cell stack.
摘要:
A minimum joint thickness can be assured by incorporating beads or particles having a diameter corresponding to the joint thickness desired and which are infusible at the brazing temperature. Preferably such particles are formed of high-melting metals, metal oxides, ceramics, or cermets and are mixed into the alloy paste prior to fusing. In a preferred embodiment, the particle-containing paste is mixed with a non-flux carrier to facilitate application to the elements to be brazed. Exemplary application methods may include painting, rolling, screening, or extrusion dispensing. Brazing alloys in accordance with the invention are useful in bonding ceramics to ceramics, ceramics to metals, and metals to metals.
摘要:
In a solid-oxide fuel cell system, the fuel cell tail gas contains significant residual amounts of combustibles which are burned in a combustor with spent cathode air to reduce system emissions and to reclaim chemical energy in the form of heat, the hot exhaust being used to pre-heat air entering the fuel cell system. The tail gas combustibles content can vary widely as can the combustion temperature. When the temperature becomes unacceptably low, a control valve in the spent cathode air return is adjusted to divert a portion of the air around the combustor, thus enriching the fuel/air mixture and causing the combustion temperature to increase. When the temperature becomes unacceptably high, a control valve in the combustor fresh air supply is adjusted to provide more air, thus causing the mixture to become leaner and the combustion temperature to decrease.
摘要:
A solid-oxide fuel cell system including an integrated reforming unit comprising a hydrocarbon fuel reformer; an integral tail gas and cathode air combustor and reformer heat exchanger; a fuel pre-heater and fuel injector cooler; a fuel injector and fuel/air mixer and vaporizer; a reforming air pre-heating heat exchanger; a reforming air temperature control valve and means; and a pre-reformer start-up combustor. The integration of a plate reformer, tail gas combustor, and combustor gas heat exchanger allows for efficient operation modes of the reformer, both endothermic and exothermic as desired. The combustor gas heat exchanger aids in temperature regulation of the reformer and reduces significant thermal gradients in the unit.
摘要:
An integrated induction system for providing fluids to the cylinders in an engine comprises a casing adapted for mounting on the engine. The casing has an air inlet and a plurality of fluid outlets. A plurality of air tubes are disposed within the casing so that air entering the air inlet flows through the air tubes and respective fluid outlets to the cylinders. A fuel injection assembly is mounted within the casing to inject fuel into the air exiting the air tubes adjacent each of the fluid outlets causing a mixture of air and fuel to enter the respective cylinders.
摘要:
A fuel cell stack is provided with a plurality of fuel cell cassettes where each fuel cell cassette has a fuel cell with an anode and cathode. The fuel cell stack includes an anode supply chimney for supplying fuel to the anode of each fuel cell cassette, an anode return chimney for removing anode exhaust from the anode of each fuel cell cassette, a cathode supply chimney for supplying oxidant to the cathode of each fuel cell cassette, and a cathode return chimney for removing cathode exhaust from the cathode of each fuel cell cassette. A first fuel cell cassette includes a flow control member disposed between the anode supply chimney and the anode return chimney or between the cathode supply chimney and the cathode return chimney such that the flow control member provides a flow restriction different from at least one other fuel cell cassettes.
摘要:
An electrically-conductive mesh spacer incorporated into the hydrogen and air gas flow spaces between each anode and cathode and its adjacent interconnect in a fuel cell stack. The mesh is formed of metal strands and is formed into a predetermined three-dimensional pattern to make contact at a plurality of points on the surfaces of the electrode and the interconnect element. The formed mesh spacer is secured as by brazing to the interconnect element at a plurality of locations to form an interconnect, which preserves the pattern during assembly of a fuel cell stack. The height of the formed pattern is greater than the height of a gas flow space after fuel cell assembly, such that the mesh spacer is slightly compressed during assembly of a fuel cell stack. Because the metal mesh is both compliant and resilient, the compressed spacer is continuously urged into mechanical and electrical contact with its electrode over all temperatures and pressures to which the fuel cell assembly may be subjected during use.