Effects of Water-emulsified Fuels on Diesel Combustion Process and NOx Reduction

Effects of newly developed water-emulsified fuel on diesel combustion and NOx formation process were investigated under various equivalence ratio, ambient temperature, water content and fuel injection pressure conditions using a rapid compression machine and a total gas-sampling device. The results show emulsified fuels promote the diffusion combustion in spite of a little higher premixed combustion due to the longer ignition delay and therefore total heat release increase with short combustion duration. Emulsified fuels shorten NOx formation duration and lower final NOx concentration compared with that in diesel fuel. NOx reduction is remarkable under enhanced diffusion combustion.