Patent ID: 8500832

Claim:
A fuel reforming device for supplying materials including air and fuel to a reforming catalyst and producing reformed gas containing hydrogen and carbon monoxide at a pressure higher than atmospheric, the device comprising: a material supply means for supplying the materials to the reforming catalyst; a reforming means for producing the reformed gas by reforming the materials supplied from the material supply means, and that includes the reforming catalyst; a catalyst temperature detection means for detecting a temperature of the reforming catalyst, and an operation control means programmed to control operation of the fuel reforming device by performing a stop mode that stops driving of the material supply means and causes the production of the reformed gas to stop, a reforming mode that causes the material supply means to be driven and the reformed gas to be produced, and a stand-by mode that causes the material supply means to be driven and makes quick transition to the reforming mode possible by maintaining a temperature of the reforming catalyst to within a predetermined range with causing the reformed gas to be minimally produced, and is programmed to control a highest temperature of the reforming catalyst to within a range of 300° C. to 1200° C., during operation of the stand-by mode, and during transition between modes of the stand-by mode and the reforming mode, and wherein the operation control means includes a material control means programmed to control an air amount, fuel amount, and reforming air/fuel ratio (A/F) of materials supplied by the material supply means, and is programmed to execute operation of the stand-by mode by causing the material control means to be driven based on the temperature of the reforming catalyst detected by the catalyst temperature detection means, and wherein the material control means is programmed to control the air amount, fuel amount, and the reforming air/fuel ratio (A/F) of the materials so that the reforming air/fuel ratio (A/F)s and fuel amount (C)s of the materials supplied by the material supply means in the stand-by mode satisfy relationships of formulas (1) and (2) relative to a reforming air/fuel ratio (A/F)r and fuel amount (C)r of the materials supplied by the material supply means in the reforming mode, Formulas: ( A/F ) s >( A/F ) r (1) (C)s (C)r (2) wherein the temperature of the reforming catalyst exhibits a convex-upward characteristic so as to reach a maximum near stoichiometric, when the air/fuel ratio is made to change while keeping the fuel amount constant, and wherein the fuel amount (C)s in the stand-by mode is set to an amount so that a maximum temperature at the near stoichiometric does not exceed a catalyst operating temperature upper limit.