Internal combustion engine and a method for operation thereof

摘要

An internal combustion engine is provided with an EGR system and a system for catalytic coversion of a rich air-fuel mixture into a reformed combustible gaseous mixture rich with free hydrogen. During a low or medium engine load engine operation, the engine is operated solely by an air-gasoline mixture and with an exhaust gas recirculation at a rate not higher than a predetermined first EGR rate. During a high engine load engine operation, the reformed combustible gaseous mixture is added to the air-gasoline mixture supply and simultaneously the exhaust gas recirculation is increased to a rate higher than the predetermined first EGR rate to increase the engine output, improve the engine drivability and improve the consumption of the reformed combustible gaseous mixture. The intake manifold vacuum is electrically detected to determine the load on the engine and to control valves associated with the EGR system and reformed gas supply system.