Fuel reforming system for an internal combustion engine

Abstract

A system for converting a rich air-fuel mixture into a reformed gaseous mixture containing hydrogen forms a part of an intake system of an internal combustion engine. The system includes an intake passage divided by a dividing wall into a first and a second sub-passages for receiving relatively lean and rich parts of the rich air-fuel mixture, respectively. The first sub-passage has a sparking plug for igniting and burning the relatively lean part of the mixture to produce heat which is transferred by the dividing wall and, as occasion demands, by a heat exchanger to the relatively rich part of the mixture flowing through the second sub-passage in order that a part of the fuel is converted into reformed gaseous mixture and the remainder of the fuel is effectively vaporized. Thereafter the rich air-fuel mixture is directed to a catalyst bed disposed downstream of the first and the second sub-passages and subjected to the fuel reformation operation, wherein the fully vaporized fuel is completely converted into reformed gaseous mixture. The sub-passages and the catalyst bed are disposed in the system upstream of a throttle valve, whereby the system is protected from variation in the vacuum produced in the intake system of the engine and thus is reliably operative to produce the reformed gaseous mixture.