EGR system for internal-combustion engine
AssigneeDenso Corporation
InventorsKeitarou Minami, Hideaki Ichihara
Life of this patent
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Abstract
In an engine, an intake duct is provided with an intercooler disposed downstream of an intake air compressor. An EGR pipe is provided with an EGR valve and an EGR cooler. An ECU determines a generation of a condensed water in the EGR cooler, the generation of the condensed water in a merging portion where a fresh air and an EGR gas merge with each other, and the generation of the condensed water in the intercooler. When it is determined that the condensed water is generated in any of these portions, the ECU performs a corresponding countermeasure for restricting the generation of the condensed water.
Claims8
An EGR system for an internal combustion engine, comprising:
- a supercharging device configured to supply an intake air to be introduced into an internal combustion engine;
- an intercooler disposed downstream of an intake air compressing portion in the supercharging device, in an intake path in the internal combustion chamber, and configured to cool the intake air;
- an EGR pipe configured to recirculate a part of exhaust gas discharged from the internal combustion engine, as an EGR gas, to the intake path from an exhaust path;
- an EGR valve disposed in the EGR pipe;
- an EGR cooler disposed in the EGR pipe;
- and
- a controller including:
- a determination portion configured to determine whether the condensed water is generated in the intercooler due to cooling of a mixed gas of the EGR gas and the intake air which is raised in temperature due to a pressure rise along with a supercharging by the supercharging device, based on an I/C gas temperature and determine whether the condensed water is generated in the EGR cooler based on an EGR gas temperature;
- a first condensed-water-restricting portion configured to control a temperature of an I/C coolant flowing into the intercooler in order to adjust a temperature of the mixed gas in the intercooler in such a manner as to restrict a generation of the condensed water in the intercooler based on a first determination result of the determination portion that the condensed water is generated in the intercooler;
- and
- a second-condensed-water-restricting-portion configured to reduce the EGR gas amount in such a manner as to restrict a generation of the condensed water in the EGR cooler, based on a second determination result of the determination portion that the condensed water is generated in the EGR cooler.
Dependencies are inferred from the claim text.