Improved exhaust gas recirculation system and methods that use one or more of the engine's cylinders as dedicated EGR cylinders. All of the exhaust from the dedicated EGR cylinders is recirculated back to the engine intake. Thus, the EGR rate is constant, but the EGR mass flow may be controlled by adjusting the air-fuel ratio of the dedicated EGR cylinders or by using various variable valve timing techniques.

EGR system with dedicated EGR cylinders

The present disclosure relates to methods, apparatuses and systems to manage exhaust gas expelled from an internal combustion engine. More particularly, the present disclosure provides an exhaust gas recirculation apparatus to distribute recirculated exhaust gas in an air stream to be introduced to an internal combustion engine, with the apparatus comprising an intake passage defined by a wall structure, the wall structure including a plurality of apertures therein configured to distribute recirculated exhaust gas into the intake passage.

EGR Distributor Apparatus For Dedicated EGR Configuration

The present disclosure relates to methods, apparatuses and systems to manage exhaust gas expelled from cylinders of an internal combustion engine. An exemplary system may comprise at least one cylinder of the engine configured to operate as a dedicated exhaust gas recirculation (EGR) cylinder, and wherein substantially all exhaust gas expelled from the dedicated EGR cylinder is recirculated to an intake system of the engine. In one embodiment, the system may include a flow restrictor configured and arranged to restrict a flow of the recirculated exhaust gas to the dedicated EGR cylinder without restricting a flow of the recirculated exhaust gas to the remaining cylinders of the engine. In another embodiment, exhaust gas may be expelled from the dedicated EGR cylinder in pulsations, and the intake system may be configured to reduce an amplitude of the pulsations of the exhaust gas expelled from the dedicated EGR cylinder.

Dedicated EGR Control Strategy For Improved EGR Distribution And Engine Performance

A system (10) is provided. The system includes an internal combustion engine having an intake manifold (16) and an exhaust manifold (18) . The system also includes a high pressure turbocharger (20) having a variable geometry high pressure turbine (22) drivingly coupled to a high pressure compressor (24) , wherein the variable geometry high pressure turbine (22) is driven by a first portion of exhaust gases from the exhaust manifold (18) / wherein the high pressure compressor (24) is configured to compress an intake air and to provide the compressed intake air to the intake manifold (16) . The system also includes a low pressure turbocharger (28) having a variable geometry low pressure turbine (30) drivingly coupled to a low pressure compressor, (32) wherein the variable geometry low pressure turbine (30) is driven by a second portion of the exhaust gases from the exhaust manifold.

Turbocharged engine system and method of operation

A method includes substantially eliminating surge of a compressor and reducing specific fuel consumption and exhaust emissions of an engine by adjusting exhaust flow through an exhaust gas recirculation system, by adjusting airflow through a compressor recirculation valve, by adjusting fuel injection timing, or by adjusting a combination thereof in response to variance in a plurality of parameters. The parameters include quantity of exhaust emissions, a maximum in-cylinder pressure of the engine, an area ratio of an exhaust gas recirculation mixer of the exhaust gas recirculation system, estimated or sensed compressor surge, engine load, altitude of operation, or combinations of the parameters thereof.

System and method for operating a turbocharged engine

In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.

Engine and method of maintaining engine exhaust temperature

A method of turbo-charger surge detection may include the steps of measuring a rate of air flow through a turbo-charger compressor, measuring a temperature of the air flow, calculating a standard mass flow rate of the air flow at the rate and the temperature, measuring a pressure ratio across the turbo-charger compressor, calculating a surge mass flow rate at a surge line of the compressor at the pressure ratio, comparing the standard mass flow rate to the surge mass flow rate, and reducing an EGR flow or reducing the pressure ratio by opening a vane of the compressor if the standard mass flow rate is lower than the surge mass flow rate.

Turbo-charger surge detection

An EGR recovery system and method includes calculating a transient volume of EGR sufficient to maintain NOx emitted by an engine below a predetermined level during a period of transient operation of said engine, supplying an actual volume of EGR during said period of transient operation, measuring said actual level of EGR during said period of transient operation, calculating an EGR deficit between said transient volume of EGR and said actual of volume of EGR during said period of transient operation, integrating said EGR deficit over said period of transient operation to calculate a deficit volume of EGR, calculating a following steady-state volume of EGR sufficient to maintain NOx emitted by said engine of said engine below said predetermined level during a following period of substantially steady-state operation of said engine, and supplying said following steady-state volume of EGR plus said deficit volume of EGR during said following period of substantially steady-state operation of said engine.

Gregory J. Birky

Papers

Engine and method of maintaining engine exhaust temperature

Turbo-charger surge detection

EGR recovery system and method

Modeling and Performance Analysis of a Field-Aged Fe-Zeolite Catalyst in a Heavy Duty Diesel Engine Application