Emissions Reduction Using Multiple Stage Diesel Combustion

Emissions characteristics of a new low-NO_x diesel combustion concept termed MULDIC (MULtiple stage DIesel Combustion), were examined under high load conditions. In conventional diesel combustion, a near-stoichiometric mixture is formed during the ignition delay, which results in a large amount of NO_x generated during the ensuing premixed combustion. Moreover, there is also a region of stoichiometric mixture formed when fuel mixes with air in diffusion combustion, where NO_x is also produced. In MULDIC, premixed combustion and diffusion combustion are separated in time, and optimized independently. As a result, NO_x emissions from MULDIC were reduced to less than half the values typical of conventional diesel combustion, at the same fuel consumption.