Patent ID: 8396644

Claim:
A control device for an internal combustion engine operable with light oil or mixed fuel containing light oil, comprising: a fuel supply unit which supplies the light oil or the mixed fuel containing light oil to the internal combustion engine; a gas supply unit which supplies hydrogen to the internal combustion engine; a combustion control unit which controls combustion in the internal combustion engine by use of combustion data related to hydrogen addition concentration previously obtained from multiple combustion waveforms changing depending on the hydrogen addition concentration; and a hydrogen addition quantity determining unit which determines the addition concentration of the hydrogen to be supplied to the internal combustion engine by selecting appropriate data from the combustion data related to the hydrogen addition concentration so as to achieve high thermal efficiency based on status of the internal combustion engine, wherein the determined addition concentration of the hydrogen is in a range of 4 to 16 volume percentage relative to intake air of the internal combustion engine.