HYDROGEN GENERATOR, FUEL CELL SYSTEM, AND METHOD OF STOPPING HYDROGEN GENERATOR

摘要

A hydrogen generator in which catalyst deterioration by dew condensation can be more effectively inhibited from occurring when the generator is under a stop.  The hydrogen generator comprises: a raw-material feeder for supplying a raw material; a water feeder for supplying water; a reformer having a reforming catalyst for yielding a hydrogen-containing gas through a reforming reaction in which the raw material and water are used; a CO-decreasing device having a CO decrease catalyst for decreasing carbon monoxide contained in the hydrogen-containing gas sent from the reformer; a burner for supplying heat necessary for the reforming reaction to the reformer; a first air feeder for supplying air required for combustion to the burner; a combustion gas passage configured so that the combustion gas generated by and then discharged from the burner undergoes a heat exchange with the reformer and the CO-decreasing device in this order; and a controller which operates the first air feeder so that the temperature of the gas inside the CO-decreasing device does not fall to or below the dew point throughout the period from a stop of combustion in the burner to a start of a purging operation in which the inside of the reformer and CO-decreasing device is purged with a replacement gas.