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US 10,119,501 B2Granted
Systems and methods for controlling EGR flow during transients
AssigneeCummins Inc.
InventorsMarten H. Dane, Sudhanshu Talwar
Life of this patent
Estimating the term…
Abstract
Systems, apparatus, and methods are disclosed that include a divided exhaust engine configured to control an EGR fraction in the charge flow to the cylinders in response to an EGR fraction overshoot condition, an exhaust pressure change in the EGR loop, and/or a transient operating condition.
Claims23
A system comprising:
- an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust passage, and a turbine operatively connected to a compressor;
- wherein the EGR passage is connected to an intake system to provide an EGR flow from the at least one primary EGR cylinder to the intake system;
- wherein the intake system provides a charge flow to the at least one primary EGR cylinder and the plurality of non-primary EGR cylinders, the charge flow including an EGR fraction corresponding to an expected EGR flow from the at least one primary EGR cylinder;
- and
- a controller operably connected to the internal combustion engine, the controller including a non-transitory computer readable medium with executable instructions to determine an EGR fraction deviation condition and to divert at least a portion of the EGR flow to a secondary location via regulating a valve in response to the EGR fraction deviation condition;
- wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to a catalyst in the exhaust passage and is lower in pressure than a primary location defined as a connection of the EGR passage to the intake system.
3 more elements
A method of controlling an exhaust gas recirculation flow in an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust system, and a turbine operatively connected to a compressor, comprising:
- passing the exhaust flow from the non-primary EGR cylinders through the exhaust system to atmosphere;
- recirculating exhaust flow from the at least one primary EGR cylinder through the EGR passage to an intake system, the intake system providing a charge flow including an EGR fraction corresponding to an amount of EGR flow from the at least one primary EGR cylinder in the charge flow;
- during a transient operating condition of the internal combustion engine,
- determining with the controller an EGR fraction deviation condition in the charge flow to the plurality of non-primary EGR cylinders and the at least one primary EGR cylinder;
- mitigating the EGR fraction deviation condition whether the EGR flow is in an overshoot condition with the controller;
- and
- adjusting a valve to divert at least a portion of the EGR flow to a secondary location in response to determining the EGR fraction deviation condition;
- wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to a catalyst in the exhaust system and is lower in pressure than a primary location defined as a connection of the EGR passage to the intake system.
5 more elements
An apparatus, comprising:
- an internal combustion engine including a plurality of cylinders, at least one of the plurality of cylinders being a primary exhaust gas recirculation (EGR) cylinder connected to an intake system to provide an EGR flow that mixes with an intake flow to form a charge flow to the plurality of cylinders, and remaining ones of the plurality of cylinders being connected to an exhaust system to provide an exhaust flow to an after treatment device of the exhaust system, and a turbine operatively connected to a compressor;
- a controller comprising:
- an EGR fraction determination module determining an actual EGR fraction in the charge flow;
- an EGR fraction deviation condition module determining an EGR fraction deviation condition in response to the actual EGR fraction and an expected EGR fraction;
- and
- an EGR fraction deviation condition mitigation module outputting an EGR fraction deviation mitigation command in response to the EGR fraction deviation condition, wherein the EGR fraction deviation command is operable to control a valve to divert at least a portion of the EGR flow to a secondary location, wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to the after treatment device being downstream of the turbine in the exhaust system and is lower in pressure than a mixing location of the EGR flow with the intake flow.
3 more elements
Dependencies are inferred from the claim text.