Improvement of Combustion from Spark Ignition Engines Fueled with Dual Fuels

In the paper, the experiment of a spark ignition engine fueled with dissociated methanol gas (D.M.) and gasoline dual fuels is conducted.

A quasi-dimensional two-zone combustion model is developed to analyze the combustion process.

Engine dynamometer test results demonstrate that the engine fueled with D.M. and gasoline dual fuels can be operated at leaner mixtures. The combustion duration and ignition delay are shortened. The maximum mass burning rate of the mixture increased by 36%. And maximum 17% improvement in thermal efficiency, and low carbon monoxide CO and hydrocarbon HC emissions are obtained.

Continuous 500 cycle measurement of the combustion pressure history demonstrates that the cycle-to-cycle fluctuation of the combustion pressure is decreased considerably.