Lean and Rich Premixed Compression Ignition Combustion in a Light-Duty Diesel Engine

Lean Premixed Compression Ignition (PCI) low-temperature combustion promises to simultaneously reduce NO_x and PM emissions, while suffering a moderate penalty in fuel consumption. Similarly, opportunities exist to develop rich PCI combustion strategies which can provide the necessary exhaust constituents for aggressive regeneration of a Lean NO_x Trap (LNT). The current work highlights the development of lean and rich PCI combustion strategies. It is shown that the lean PCI combustion strategy successfully operates with low NO_x and PM, at the expense of a 5% increase in fuel consumption over conventional diesel operation. The rich PCI combustion strategy similarly operates with low NO_x and PM, and produces enough CO (up to 5% by volume in exhaust) for aggressive regeneration of an LNT.