摘要:
A solid-oxide fuel cell system wherein a reformate combustor is disposed in the reformate flow path between a hydrocarbon reformer and a fuel cell stack. At system start-up, reformate is partially burned within the combustor by admitting combustion air, and the partially-burned reformate is passed through the anode chambers of the stack to warm the anodes. In addition, reformate is passed through a cathode-air heat exchanger to warm combustion air entering the cathode chambers of the stack. The combustor may continue to be supplied with a low level of air during steady-state operation of the SOFC, thereby providing a moist environment within the anode chambers to prevent coking of the anodes and providing additional heat to the reformate. The combustor decouples the reformer from the stack thermodynamically, permitting the reformer and the stack each to run in its own optimal temperature range.
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 method for forming a solid oxide fuel cell stack from a plurality of individual solid oxide fuel cells, wherein the anodes of the solid oxide fuel cells are infiltrated by one or more materials for making the anodes less sensitive to sulfur poisoning and/or less subject to carbon degradation and/or for improving the electrochemical performance of the stack, the method comprising the steps of oxidizing the anodes of the individual solid oxide fuel cells before forming a stack, building a solid oxide fuel cell stack with all of the anodes in an oxidized state, reducing all of the anodes, and then infiltrating all of the anodes with at least one of the materials.
摘要:
A method for forming a solid oxide fuel cell stack from a plurality of individual solid oxide fuel cells, wherein the anodes of the solid oxide fuel cells are infiltrated by one or more materials for making the anodes less sensitive to sulfur poisoning and/or less subject to carbon degradation and/or for improving the electrochemical performance of the stack, the method comprising the steps of oxidizing the anodes of the individual solid oxide fuel cells before forming a stack, building a solid oxide fuel cell stack with all of the anodes in an oxidized state, reducing all of the anodes, and then infiltrating all of the anodes with at least one of the materials.
摘要:
A method for preparing an interconnect is provided. The method comprises: providing a conductive base sheet including a first face and a second face, the first and second faces are disposed on opposite sides of the base sheet; preparing anode gas flow passages on the first face of the conductive base sheet; preparing cathode gas flow passages on the second face of the conductive base sheet; and selecting anode gas flow passage geometry having a first geometric configuration; and selecting cathode gas flow passage geometry having a second geometric configuration that is different from the first geometric configuration so as to optimize fuel and oxidant gas flow according to system requirements.
摘要:
In a fuel cell assembly, nickel-based anodes are readily oxidized when exposed to oxygen as may happen through atmospheric invasion of the assembly during cool-down following shutdown of the assembly. Repeated anode oxidation and reduction can be destructive of the anodes, leading to cracking and failure. To prevent such oxygen migration, check valves and oxygen getter devices containing oxygen-scavenging material such as metallic nickel are provided in the reformate passageways leading to and from the anodes. The check valves preferably are closed by gravity. Oxidation of the oxygen-gettering material is readily reversed through reduction by reformate when the assembly is restarted.
摘要:
A method of starting a solid oxide fuel cell system is disclosed. The method comprises pressurizing a main plenum to a first pressure. The main plenum comprises a first supply of fuel, blowers, and air control valves. The first supply of fuel and a first supply of air are directed to a preheated micro-reformer. A heated pre-reformate is created in the micro-reformer and discharged from the micro-reformer to a main reformer. The main reformer is preheated with the heated pre-reformate. A second supply of fuel and a second supply of air are introduced to the main reformer. A heated main reformate is created in the main reformer and directed to a waste energy recovery assembly. A cathode supply is heated in the waste energy recovery system and then directed to a solid oxide fuel cell stack in order to heat the solid oxide fuel cell stack. Methods of transitioning, operating, shutting down, and maintaining in standby mode are also disclosed. A solid oxide fuel cell mechanization for a transportation vehicle is also disclosed.
摘要:
A system for adding sulfur to a fuel cell stack, having a reformer adapted to reform a hydrocarbon fuel stream containing sulfur contaminants, thereby providing a reformate stream having sulfur; a sulfur trap fluidly coupled downstream of the reformer for removing sulfur from the reformate stream, thereby providing a desulfurized reformate stream; and a metering device in fluid communication with the reformate stream upstream of the sulfur trap and with the desulfurized reformate stream downstream of the sulfur trap. The metering device is adapted to bypass a portion of the reformate stream to mix with the desulfurized reformate stream, thereby producing a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.