Fast acting exhaust gas recirculation system

A heavy-duty diesel engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders and an exhaust gas recirculation (EGR) system for supplying recirculated exhaust gas to the cylinders, each cylinder having an intake port, the EGR system comprising:

• an EGR line coupled with the exhaust manifold to receive a portion of the exhaust gas flowing from the exhaust manifold
• an EGR cooler coupled with the EGR line operable to cool only recirculated exhaust gas;
• a plurality of exhaust gas conduits, each extending from the EGR line to an associated intake port, the junction of each exhaust gas conduit and each intake port being proximate to an associated cylinder;
• a plurality of EGR control valves, a control valve disposed within each exhaust gas conduit for controlling only recirculated exhaust gas flow to the associated cylinder;
• and
• an engine control unit for regulating the position of each metering valve to vary the flow of recirculated exhaust gas supplied to each intake port in response to changes in operating conditions of the engine.

A method for controlling recirculation of exhaust gas in an internal combustion engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders, comprising:

• supplying intake air to the intake manifold;
• directing a first portion of exhaust gas flowing from the exhaust manifold to an exhaust gas recirculation line;
• storing a portion of the exhaust gas flowing through the exhaust gas recirculation line in a reservoir to provide a supply of recirculated exhaust gas;
• supplying recirculated exhaust gas from the reservoir to each cylinder through a respective exhaust gas conduit;
• and
• controlling the flow of recirculated exhaust gas to each cylinder by a respective metering valve disposed in each exhaust gas conduit;
• wherein the supplying step is performed by performing the following steps:
• supplying at least a second portion of the exhaust gas from the exhaust manifold to a turbine in a turbocharger having a compressor that is operated by the turbine, supplying compressed air from the compressor to the intake manifold, communicating exhaust gas flowing from the turbine through a filter trap to remove particulate matter from the exhaust gas, and directing the first portion of the exhaust gas flowing from the exhaust manifold through the exhaust gas recirculation line prior to the second portion of the exhaust gas entering the turbine.

A method for controlling recirculation of exhaust gas in an internal combustion engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders, comprising:

• supplying intake air to the intake manifold;
• directing a first portion of exhaust gas flowing from the exhaust manifold to an exhaust gas recirculation line;
• storing a portion of the exhaust gas flowing through the exhaust gas recirculation line in a reservoir to provide a supply of recirculated exhaust gas;
• supplying recirculated exhaust gas from the reservoir to each cylinder through a respective exhaust gas conduit;
• and
• controlling the flow of recirculated exhaust gas to each cylinder by a respective metering valve disposed in each exhaust gas conduit;
• wherein the supplying step is performed by performing the following steps:
• supplying exhaust gas from the exhaust manifold to a turbine in a turbocharger having a compressor that is operated by the turbine, supplying compressed air from the compressor to the intake manifold, communicating exhaust gas flowing from the turbine through a filter trap to remove particulate matter from the exhaust gas, and directing the portion of the exhaust gas flowing from the exhaust manifold through the exhaust gas recirculation line after the exhaust gas exits from the filter trap.

A method for controlling recirculation of exhaust gas in an internal combustion engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders, comprising:

• supplying intake air to the intake manifold;
• directing a first portion of exhaust gas flowing from the exhaust manifold to an exhaust gas recirculation line;
• storing a portion of the exhaust gas flowing through the exhaust gas recirculation line in a reservoir to provide a supply of recirculated exhaust gas;
• supplying recirculated exhaust gas from the reservoir to each cylinder through a respective exhaust gas conduit;
• controlling the flow of recirculated exhaust gas to each cylinder by a respective metering valve disposed in each exhaust gas conduit;
• and
• cooling recirculated exhaust gas stored in the reservoir to a desired temperature.

A method for controlling recirculation of exhaust gas in an internal combustion engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders, comprising:

• supplying intake air to the intake manifold;
• directing a first portion of exhaust gas flowing from the exhaust manifold to an exhaust gas recirculation line;
• storing a portion of the exhaust gas flowing through the exhaust gas recirculation line in a reservoir to provide a supply of recirculated exhaust gas;
• supplying recirculated exhaust gas from the reservoir to each cylinder through a respective exhaust gas conduit;
• controlling the flow of recirculated exhaust gas to each cylinder by a respective metering valve disposed in each exhaust gas conduit;
• and
• mixing recirculated exhaust gas supplied to each cylinder with intake air within an intake port of the respective cylinder.

A method for controlling recirculation of exhaust gas in an internal combustion engine having a plurality of cylinders with an intake manifold and an exhaust manifold coupled with the cylinders, comprising:

• supplying intake air to the intake manifold;
• directing a first portion of exhaust gas flowing from the exhaust manifold to an exhaust gas recirculation line;
• storing a portion of the exhaust gas flowing through the exhaust gas recirculation line in a reservoir to provide a supply of recirculated exhaust gas;
• supplying recirculated exhaust gas from the reservoir to each cylinder through a respective exhaust gas conduit;
• controlling the flow of recirculated exhaust gas to each cylinder by a respective metering valve disposed in each exhaust gas conduit;
• forming a respective intake port between the intake manifold and the cylinder;
• forming a flow restriction within each intake port selected from the group consisting of a venturi, a nozzle, or an orifice, to form a low pressure area within the respective intake port;
• and
• injecting recirculated exhaust gas into the low pressure area.