Abstract: A method is provided for generating rapid light-off for a diesel oxidation catalyst (DOC) close-coupled to a compression-ignition engine. The engine includes an intake passage in fluid communication with a combustion chamber, a throttle for controlling a flow of intake air through the intake passage, and an exhaust passage configured to channel an exhaust gas from the combustion chamber to the DOC. The method includes starting the engine to commence a warm-up thereof and regulating the throttle to restrict supply of the intake airflow to the combustion chamber. The method additionally includes injecting a predetermined amount of fuel into the combustion chamber during the engine's exhaust cycle such that the injected fuel is carried by the exhaust gas and burned in the exhaust passage. Regulating the throttle and injecting fuel during the warm-up of the engine together increase temperature of the exhaust gas for rapid light-off of the close-coupled DOC.

Abstract: A method is provided for generating rapid light-off for a diesel oxidation catalyst (DOC) close-coupled to a compression-ignition engine. The engine includes an intake passage in fluid communication with a combustion chamber, a throttle for controlling a flow of intake air through the intake passage, and an exhaust passage configured to channel an exhaust gas from the combustion chamber to the DOC. The method includes starting the engine to commence a warm-up thereof and regulating the throttle to restrict supply of the intake airflow to the combustion chamber. The method additionally includes injecting a predetermined amount of fuel into the combustion chamber during the engine's exhaust cycle such that the injected fuel is carried by the exhaust gas and burned in the exhaust passage. Regulating the throttle and injecting fuel during the warm-up of the engine together increase temperature of the exhaust gas for rapid light-off of the close-coupled DOC.

Abstract: An exhaust system includes a selective catalytic reduction (SCR) unit and a NOx absorber that may include a lean NOx trap (LNT). The NOx absorber absorbs NOx and releases the NOx absorbed in the NOx absorber into the SCR unit. The SCR unit converts NOx of exhaust gas into nitrogen and water.

Abstract: An exhaust system includes a selective catalytic reduction (SCR) unit and a NOx absorber that may include a lean NOx trap (LNT). The NOx absorber absorbs NOx and releases the NOx absorbed in the NOx absorber into the SCR unit. The SCR unit converts NOx of exhaust gas into nitrogen and water.

Abstract: A compression-ignition internal combustion engine for conducting pilot injection and main injection beyond the top dead center, wherein pilot injection quantity and timing are optimized. A compression-ignition internal combustion engine, comprising a fuel injection valve for injecting fuel into a combustion chamber in a cylinder, the quantity and timing of the fuel injected through the fuel injection valve being controlled based on engine operating conditions; wherein pilot injection is carried out prior to the top dead center of compression, main injection is then carried out beyond the top dead center of compression, and fuel injection quantity and fuel injection timing of the pilot injection are set such that the maximum rate of heat release induced by the pilot injection is 60 kJ/s or less.

Abstract: A compression-ignition internal combustion engine for conducting pilot injection and main injection beyond the top dead center, wherein pilot injection quantity and timing are optimized. A compression-ignition internal combustion engine, comprising a fuel injection valve for injecting fuel into a combustion chamber in a cylinder, the quantity and timing of the fuel injected through the fuel injection valve being controlled based on engine operating conditions; wherein pilot injection is carried out prior to the top dead center of compression, main injection is then carried out beyond the top dead center of compression, and fuel injection quantity and fuel injection timing of the pilot injection are set such that the maximum rate of heat release induced by the pilot injection is 60 kJ/s or less.