Spray Combustion Behaviors of Diesel and Dialkyl Carbonate Blends in a Constant Volume Chamber

Dialkyl carbonate is a potential renewable alternative fuel for transportation. This study, utilizing a constant volume combustion chamber, investigates the characteristics of spray auto-ignition of dialkyl carbonate when mixed with diesel fuel. Measurements of combustion pressures and heat release rates during fuel spray combustion were conducted at varied conditions of fuel blending percentage, ambient temperature and pressure, injection pressure, and oxidizing atmospheres. The study also derives and compares ignition and combustion delays from pressure traces for different fuel blends. Results indicate that blending dialkyl carbonate with diesel fuel reduces ignition tendency, supported by delayed pressure rise and heat release processes with increased blending percentage of dialkyl carbonate. Further, at lower blending percentages of dialkyl carbonate, fuel ignition and combustion delays are insensitive to changes in injection pressure, but fuel combustion delay is significantly shortened with increased injection pressure at higher blending percentages. Finally, in an oxidizing atmosphere of CO2/O2 mixtures, fuel spray combustion processes are retarded, and this retardance is noticeable at higher dialkyl carbonate blending percentages.