Caterpillar Inc.
Engine system, combustion control system, and operating method with close-coupled early pilots and cylinder temperature control

Abstract:

Operating a direct-injection compression-ignition engine includes injecting early pilot shots of fuel, and controlling a cylinder temperature timing to combust the early pilot shots according to a combustion phasing that is based on the cylinder temperature timing. A main charge of the fuel is combusted based on the combustion of the early pilot shots. A combustion control unit is structured to command actuation of a fuel injector and a cylinder temperature controller to phase combustion of early pilot shots of the fuel, prior to a TDC position of a piston in an engine cycle. The cylinder temperature controller is a variable valve actuator or other apparatus controlling cylinder temperature in a manner decoupled from piston position.