An embodiment apparatus for reducing fouling of an exhaust gas recirculation (EGR) cooler includes an exhaust gas transfer part configured to connect a diesel oxidation catalyst (DOC) of an exhaust gas post-treatment system extending from an engine through an exhaust line to an EGR cooler installed in an EGR line and configured to recirculate exhaust gas discharged from an exhaust manifold to an intake manifold, a valve installed in the exhaust gas transfer part, and a controller configured to selectively open the valve as the exhaust gas post-treatment system enters a predetermined diesel particulate filter (DPF) regeneration condition and allow exhaust gas discharged from the DOC to be supplied to the EGR cooler through the exhaust gas transfer part.

Methods and systems are provided for determining changes in a flow area of an exhaust gas recirculation (EGR) valve for EGR flow estimates due to soot accumulation on the EGR valve. In one example, a method includes indicating soot accumulation on the EGR valve based on a difference in EGR flow estimated with an intake oxygen sensor and with a pressure sensor coupled across the EGR valve. The determination of the difference of the EGR flow estimates may occur when the engine is not boosted.

Methods and systems are provided for determining changes in a flow area of an exhaust gas recirculation (EGR) valve for EGR flow estimates due to soot accumulation on the EGR valve. In one example, a method includes indicating soot accumulation on the EGR valve based on a difference in EGR flow estimated with an intake oxygen sensor and with a pressure sensor coupled across the EGR valve. The determination of the difference of the EGR flow estimates may occur when the engine is not boosted.

An internal combustion engine includes, in addition to an LPL-EGR system, two water vapor separation film modules for fresh air and for EGR gas. One module 34 is connected to a pressure reducing pump 40 through a suction passage 38. Other module 36 is connected to a pressure reducing pump 44 through a suction passage 42. A condenser 54 that condenses water vapor that flows through the suction passage 38 is provided in the suction passage 38. A water tank 56 that temporarily accumulates condensed water that is discharged from the condenser 54 is provided on a downstream side relative to the condenser 54. The water tank 56 is connected to injectors 60 that inject water from the water tank 56 into intake ports of respective cylinders or into respective cylinders.

An internal combustion engine includes, in addition to an LPL-EGR system, two water vapor separation film modules for fresh air and for EGR gas. One module 34 is connected to a pressure reducing pump 40 through a suction passage 38. Other module 36 is connected to a pressure reducing pump 44 through a suction passage 42. A condenser 54 that condenses water vapor that flows through the suction passage 38 is provided in the suction passage 38. A water tank 56 that temporarily accumulates condensed water that is discharged from the condenser 54 is provided on a downstream side relative to the condenser 54. The water tank 56 is connected to injectors 60 that inject water from the water tank 56 into intake ports of respective cylinders or into respective cylinders.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A fuel reforming system includes a fuel injection device capable of injecting fuel into an EGR passage, a reforming catalyst provided in the EGR passage, an oxidation catalyst provided in the vicinity of the reforming catalyst in the EGR, and an air supply device that supplies air to the EGR passage. When clogging occurs in the reforming catalyst and a temperature of the reforming catalyst is less than a first temperature, air is supplied to the EGR passage by the air supply device, and fuel is injected by the fuel injection device. When clogging occurs in the reforming catalyst and the temperature of the reforming catalyst is greater than or equal to the first temperature, air is supplied to the EGR passage by the air supply device, and fuel injection of the fuel injection device is stopped.

A fuel reforming system includes a fuel injection device capable of injecting fuel into an EGR passage, a reforming catalyst provided in the EGR passage, an oxidation catalyst provided in the vicinity of the reforming catalyst in the EGR, and an air supply device that supplies air to the EGR passage. When clogging occurs in the reforming catalyst and a temperature of the reforming catalyst is less than a first temperature, air is supplied to the EGR passage by the air supply device, and fuel is injected by the fuel injection device. When clogging occurs in the reforming catalyst and the temperature of the reforming catalyst is greater than or equal to the first temperature, air is supplied to the EGR passage by the air supply device, and fuel injection of the fuel injection device is stopped.

An EGR device includes a plurality of EGR inlet pipes connected to each of the plurality of intake branch passages, an exhaust gas inlet passage conveying a portion of the exhaust gas as EGR gas, an upstream-side branch passage in communication with the exhaust gas inlet passage and branching the EGR gas, and a downstream-side branch passage distributing the EGR gas branched in the upstream-side branch passage to the plurality of EGR inlet pipes. The downstream-side branch passage extends in a direction parallel to an arrangement direction of the plurality of cylinders. At least one of the exhaust gas inlet passage and the upstream-side branch passage is configured to suppress flow to a downstream side of condensed water located upstream of the downstream-side branch passage when acceleration in a direction parallel to the arrangement direction is applied to the internal combustion engine.