Patent ID: 7533518

Claim:
In a mechanical apparatus including a diesel engine having a combustion chamber, the mechanical apparatus also including an aftertreatment device configured to treat emissions from the diesel engine, a method of operating the engine, comprising: operating the engine with an early homogenization combustion mode; determining a temperature of the aftertreatment device; and if the temperature of the aftertreatment device is equal to or below a preselected temperature threshold, then performing at least one late homogenization combustion in the combustion chamber to raise a temperature of exhaust provided to the aftertreatment device, while continuing operating the engine with the early homogenization combustion mode, the late homogenization combustion including a combustion mode where fuel is directly injected into the combustion chamber, a substantial portion of in-cylinder fuel and air mixing occurs after top dead center, and combustion occurs during the expansion stroke, wherein performing includes, in a single engine cycle, directly injecting fuel into the combustion chamber at a late homogenization combustion timing and injecting fuel into the combustion chamber at an early homogenization combustion timing, wherein the preselected temperature threshold is adjusted as a function of an aging of the aftertreatment device.