Effects of Fuel Chemical Composition on Basic and Abnormal Combustion Properties in Dimethyl Carbonate and Existing Fuels

Abstract

The objective of this study is to investigate in detail the basic combustion characteristics and abnormal combustion characteristics in the engine cylinder during drop-in of a synthetic fuel, dimethyl carbonate, at varying content rates to an existing fuel, Primary Reference Fuel (PRF). An optically accessible engine capable of flame propagation velocity analysis was used for the experiment, and combustion analysis was performed by visualization in the engine cylinder and in-cylinder pressure data acquisition. As a result, the experiments showed that the flame propagation velocity in the actual engine slowed down as DMC was included. Next, under the condition of 40% DMC content and less influence of residual gas, the knock resistance was not improved, and the knocking intensity was higher than that of the existing fuel. Finally, under conditions with 80% DMC content and high residual gas in the cylinder, combustion variation and misfire cycles were found to increase. The cause was found to be a prolonged initial combustion period.