Systems, methods and apparatus for controlling operation of an engine structured to combust gaseous fuel such as a dual fuel engine, including an estimation of key parameters dependent on natural gas quality, are disclosed. The natural gas quality parameters are estimated from natural gas properties obtained from various sensed parameters associated with the engine.

The disclosure relates to an exhaust gas conduction system for a gasoline engine, comprising an exhaust gas line which can be connected to an exhaust manifold of the gasoline engine, an intake line which can be connected to an intake manifold of the gasoline engine, a charge air compressor which is arranged in the intake line, and a turbine which is arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve, said line branching off from the exhaust gas line upstream of the turbine and branching back into the exhaust gas line at an opening downstream of the turbine. At least one exhaust gas recirculation line with an EGR throttle valve is provided, said line opening into the intake line, wherein the exhaust gas recirculation line branches off from the bypass line at a branch, and the bypass throttle valve is arranged upstream of the branch of the exhaust gas recirculation line. At least one particle filter is arranged in the bypass line downstream of the branch of the exhaust gas recirculation line, and an exhaust gas valve is provided in the exhaust gas line upstream of the opening of the bypass line.

The disclosure relates to an exhaust gas conduction system for a gasoline engine, comprising an exhaust gas line which can be connected to an exhaust manifold of the gasoline engine, an intake line which can be connected to an intake manifold of the gasoline engine, a charge air compressor which is arranged in the intake line, and a turbine which is arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve, said line branching off from the exhaust gas line upstream of the turbine and branching back into the exhaust gas line at an opening downstream of the turbine. At least one exhaust gas recirculation line with an EGR throttle valve is provided, said line opening into the intake line, wherein the exhaust gas recirculation line branches off from the bypass line at a branch, and the bypass throttle valve is arranged upstream of the branch of the exhaust gas recirculation line. At least one particle filter is arranged in the bypass line downstream of the branch of the exhaust gas recirculation line, and an exhaust gas valve is provided in the exhaust gas line upstream of the opening of the bypass line.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

An exhaust gas recirculation system for a gasoline engine, including an exhaust gas line, which can be connected to an exhaust manifold of the gasoline engine and which includes a turbine, and an inlet line, which can be connected to an intake manifold of the gasoline engine and which includes a compressor. A main exhaust gas catalytic converter is provided in the exhaust gas line, and at least one exhaust gas recirculation line_I is provided which branches off from the exhaust gas line upstream of the turbine and opens into the inlet line downstream of the compressor. At least one particle filter_I is provided which is placed in the exhaust gas recirculation line_I or in the exhaust gas line upstream of the exhaust gas recirculation line_I. The particle filter_I has a 3/Ox coating, and at least one cooler_I is provided within the exhaust gas recirculation line_I downstream of the at least one particle filter.

An EGR device includes a housing having an outer pipe and an inner pipe. The inner pipe is accommodated in the outer pipe to define an annular passage externally with the outer pipe. The inner pipe defines an inner passage internally. The inner pipe has pipe through holes. A rotary valve is accommodated in the inner pipe. The rotary valve has valve through holes. The rotary valve is rotatable to communicate the annular passage with the inner passage through the valve through holes and the pipe through holes. The rotary valve is rotatable to block the inner passage from the annular passage.

Methods and systems are provided for regulating airflow through a charge air cooler integrated in an intake assembly. In one example, an engine intake assembly comprises a plenum having an integrated charge air cooler (CAC), a first header seal positioned around a circumference of a first CAC header, and a first rotatably movable seal positioned in a bypass passage of the plenum. The first movable seal interfaces via sliding contact with the first header seal and adjusting a position of the first movable seal may vary the amount of airflow through the bypass passage.

Methods and systems are provided for regulating airflow through a charge air cooler integrated in an intake assembly. In one example, an engine intake assembly comprises a plenum having an integrated charge air cooler (CAC), a first header seal positioned around a circumference of a first CAC header, and a first rotatably movable seal positioned in a bypass passage of the plenum. The first movable seal interfaces via sliding contact with the first header seal and adjusting a position of the first movable seal may vary the amount of airflow through the bypass passage.

A system and method for providing torque-assist to a rotary shaft of an internal combustion engine control an electric machine in response to operation of an exhaust gas recirculation (EGR) valve to assist the rotation of the rotary shaft. The system and method facilitate periodic operation of the EGR valve to purge condensation without objectionable torque reduction when the engine is operating near full load.