NOVELTY - A fuel cell system comprises a fuel reforming reactor; a direct water vaporizing combustor having a fuel injector, an air inlet and water injector and additionally includes a water gas shift reactor; a second direct water vaporizing combustor and a fuel cell.    USE - In fuel cells to facilitate rapid startup of e.g. automobiles, trucks and for producing steam for use in a fuel reforming reactor or fuel reformate purification equipment.    ADVANTAGE - The fuel processing system is capable of rapidly producing substantial amounts of heat and hydrogen to quickly achieve high operating temperatures necessary for startup, and is capable of producing substantial amounts of heat and hydrogen necessary to respond to dramatic increases in electrical load demand on the fuel cell during transient conditions. The direct water vaporizing combustor is capable of directly vaporizing sprayed water without the use of a heat exchanger to produce steam.    DETAILED DESCRIPTION - The fuel reforming processor has a catalyst constructed and arranged to produce a reformate stream including hydrogen and carbon monoxide. The water gas shift reactor is placed downstream of the fuel reforming processor and it includes a catalyst constructed and arranged to reduce the amount of carbon monoxide in the reformate stream. The first direct water vaporizing combustor is constructed and arranged to combust fuel producing a high-temperature fuel combustion byproduct exhaust, to produce steam from water sprayed into the combustion byproduct exhaust and the combustor is plumbed to the fuel reforming reactor to charge steam and the second direct water vaporizing combustor is constructed and arranged to combust a fuel to produce a high-temperature fuel combustion byproduct exhaust and to produce steam from water sprayed into the fuel combustion byproduct exhaust in which the second direct water vaporizing combustor is plumbed to the water gas shift reactor to charge steam. The fuel cell stack is arranged downstream of a preferential oxidation reactor constructed and arranged to produce electricity from the hydrogen-rich stream. The preferential oxidation reactor is arranged downstream of the water gas shift reactor and it includes a catalyst constructed and arranged to preferentially oxidize carbon monoxide into carbon dioxide and to produce a hydrogen-rich stream.