Emission Reduction Using Multiple Stage Diesel Combustion.

A new diesel combustion concept termed MULDIC (MULtiple stage Diesel Combustion), which reduces NOx emissions at high load conditions, was studied. In conventional diesel combustion, a near stoichiometric mixture is formed during the ignition delay, and generates a large amount of NOx during the premixed combustion. Moreover, there is also a region of stoichiometric mixture when fuel mixes with air in diffusion combustion, where NOx is also produced. In MULDIC, premixed combustion and diffusion combustion are separated in time, and optimized independently. As a result, NOx emissions from MULDIC were reduced to less than half values of conventional diesel combustion at the same fuel consumption.