Cooler bypass to reduce condensate in a low-pressure EGR system
AssigneeFord Global Technologies, LLC
InventorEric Matthew Kurtz
Life of this patent
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Abstract
Various systems and methods are described for an exhaust gas recirculation (EGR) system including an EGR cooler coupled to a turbocharged engine in a vehicle. One example method comprises, under selected operating conditions, controlling a mixture temperature of cooled and uncooled EGR at a mixing location upstream of an intake passage inlet by routing at least a portion of exhaust gas through a bypass around the EGR cooler.
Claims21
A method for an exhaust gas recirculation (EGR) system including an EGR cooler coupled to a turbocharged engine in a vehicle, comprising:
- under selected EGR coolant temperatures, controlling a mixture temperature of cooled and uncooled EGR at a mixing location upstream of an intake passage inlet by routing at least a portion of exhaust gas through a bypass around the EGR cooler, wherein a desired mixture temperature is based on an EGR coolant temperature.
A method for an exhaust gas recirculation (EGR) system including an EGR cooler coupled to a turbocharged engine in a vehicle, comprising:
- under selected operating conditions, controlling a mixture temperature of cooled and uncooled EGR at a mixing location upstream of an intake passage inlet by routing at least a portion of exhaust gas through a bypass around the EGR cooler;
- and
- estimating the mixture temperature based on a temperature of exhaust gas entering the EGR cooler, a temperature of exhaust gas exiting the EGR cooler, and an amount of exhaust gas passing through the bypass and an amount of exhaust gas passing through the EGR cooler.
A method for a low-pressure exhaust gas recirculation (LP-EGR) system including an LP-EGR cooler coupled to a turbocharged engine in a vehicle, comprising:
- under selected operating conditions:
- routing a first amount of EGR through the LP-EGR cooler;
- routing a second amount of EGR through a bypass around the LP-EGR cooler to a location downstream of the LP-EGR cooler and upstream of an intake passage inlet to mix with the first amount of EGR and generate a first mixture of cooled EGR and uncooled EGR;
- delivering the first mixture to the intake passage where it is mixed with fresh air to generate a second mixture;
- adjusting a first valve based on a temperature of the first mixture;
- and
- adjusting a second valve based on a temperature of the second mixture.
A system for an engine in a vehicle, comprising:
- a turbocharger;
- a low-pressure exhaust gas recirculation (LP-EGR) system including an LP-EGR cooler and an LP-EGR cooler bypass;
- an LP-EGR cooler bypass valve;
- a control system comprising a computer readable storage medium, the medium comprising instructions for, under selected operating conditions:
- routing a first amount of EGR through the cooler;
- routing a second amount of EGR through the cooler bypass to a location downstream of the cooler and upstream of an intake passage inlet to generate a first mixture of cooled EGR and uncooled EGR;
- delivering the first mixture to the intake passage where it is mixed with fresh air to generate a second mixture;
- adjusting a first valve based on a temperature of the first mixture;
- and
- adjusting a second valve based on a temperature of the second mixture.
Dependencies are inferred from the claim text.