Methods and systems are provided for regenerating and purging a particulate filter of an exhaust treatment system for a combustion engine. In one example, a method may include flowing exhaust gas in a reverse direction through the particulate filter to purge particulate matter to an intake manifold of the engine for combusting. The duration of purging may be based on a regeneration achieved during a previous regeneration of the particulate filter during a deceleration fuel shut-off event.

Engine low pressure cooled exhaust gas recirculation (LPCEGR) control techniques comprise receiving a measured position of an accelerator pedal and, based on this measurement, detecting a transient tip-out event or a transient tip-in event. In response to detecting the transient tip-out event, an EGR depletion rate is temporarily increased by at least one of (i) downstream throttle valve control to maintain at least a minimum engine airflow or to regulate a rate of decrease of the airflow into the engine, (ii) cylinder bank fuel shutoff, and (iii) pre-scheduled EGR valve control based on the measured accelerator pedal position. In response to detecting the transient tip-in event, an EGR delivery rate is temporarily increased by at least one of (i) the pre-scheduled EGR valve control and (ii) controlling intake/exhaust valves of cylinders of the engine to enable a scavenging mode.

An exhaust system includes a first exhaust after-treatment system receiving exhaust gases generated by an engine, a second exhaust after-treatment system downstream of the first exhaust after-treatment system, and at least one bypass connecting an engine outlet to an inlet to the second exhaust after-treatment system. A turbocharger is associated with the bypass and a bypass valve is located upstream of the turbocharger. The bypass valve is moveable between an open position to bypass exhaust gas flow to the first exhaust after-treatment system, a closed position to direct all exhaust gas flow to the first exhaust after-treatment system, and a partially open position where one portion of exhaust gas flow is directed into the first exhaust after-treatment system and a remaining portion of exhaust gas flow is directed into the turbocharger. A controller controls movement of the bypass valve between the open, closed, and partially open positions.

Methods and systems are provided for regenerating an exhaust particulate filter during an engine non-combusting condition. In one example, a method may include, responsive to a higher than first threshold soot load on the PF and a higher than threshold PF temperature, regenerating the PF by flowing compressed air through the PF via operation of an electric booster coupled to the intake manifold.

Methods and systems are provided for expediting exhaust particulate filter regeneration. In one example, an engine controller may generate an exotherm at the filter by operating engine cylinders with air-fuel imbalance while using electric assist to a turbocharger to meet a torque demand and raise an intake airflow to enhance the effect of the exotherm. Once heated, the filter may be regenerated by flowing extra air to the exhaust via an air pump and injecting extra fuel to an exhaust passage via an exhaust injector.

Methods and systems are provided for regenerating an exhaust particulate filter during an engine non-combusting condition. In one example, a method may include, responsive to a higher than first threshold soot load on the PF and a higher than threshold PF temperature, regenerating the PF by flowing compressed air through the PF via operation of an electric booster coupled to the intake manifold.

A variable position device (25) for a turbocharger includes a turbine wheel (24). A fluid diverter (26) for diverting exhaust gas flow to the turbine wheel (24) is moveable inclusively between a first and a second end-stop position (80, 104, 82, 106) defining an end-stop span (84, 108). An actuator (46) is in operable association with the fluid diverter (26). The actuator (46) is configure to, in an operation mode, selectively move the fluid diverter (26) inclusively between a first and a second guard band position (88, 110, 90, 112) defining a guard band span (92, 114) that is less than the end-stop span (84, 108). The actuator (46) is configured to, in a first mode, move the fluid diverter (26) to a first reduced guard band position (94, 116) that is inclusively between the first end-stop position (80, 104) and the first guard band position (88, 110), and apply a constant force to the fluid diverter (26) to hold the fluid diverter (26) in the first reduced guard band position (94, 116).

An embodiment of an exhaust handling system for a marine vessel includes a cap connected to a top end portion of an exhaust stack of the marine vessel to form an enclosure at least partially surrounding an outlet of an exhaust pipe extending through the exhaust stack. In addition, the exhaust handling system includes a collection pipe in fluid communication with the cap such that the collection pipe is to receive exhaust from the enclosure, and a coupling connected to the collection pipe that is to connect to an exhaust cleaning assembly. The exhaust cleaning system includes a tank to receive the exhaust. The cap at least partially defines a first flow path for the exhaust that extends from the enclosure to the atmosphere. The collection pipe at least partially defines a second flow path for the exhaust that extends from the enclosure to the coupling via the collection pipe.

Methods and systems are provided for regenerating and purging a particulate filter of an exhaust treatment system for a combustion engine. In one example, a method may include flowing exhaust gas in a reverse direction through the particulate filter to purge particulate matter to an intake manifold of the engine for combusting. The duration of purging may be based on a regeneration achieved during a previous regeneration of the particulate filter during a deceleration fuel shut-off event.

Methods and systems are provided for expediting exhaust particulate filter regeneration. In one example, an engine controller may generate an exotherm at the filter by operating engine cylinders with air-fuel imbalance while using electric assist to a turbocharger to meet a torque demand and raise an intake airflow to enhance the effect of the exotherm. Once heated, the filter may be regenerated by flowing extra air to the exhaust via an air pump and injecting extra fuel to an exhaust passage via an exhaust injector.