A Study of Combustion of Hydrogen-Enriched Gasoline in a Spark Ignition Engine

An investigation has been done on the influence of small amounts of hydrogen added to hydrocarbons-air mixtures on combustion characteristics.

The effect of hydrogen addition to a hydrocarbon-air mixture was firstly approached in an experimental bomb, to measure the laminar burning velocity and the shift of lean flammability limit.

Experiments carried out with a single-cylinder four stroke SI engine confirmed the possibility of expanding the combustion stability limit, which correlates well with the general trend of enhancing the rate of combustion. An increase of brake thermal efficiency has been obtained with a reduction of HC emissions; the NO_x emissions were higher, except for very lean mixtures.