A system and method for preventing a failure of an exhaust heat recovery device are provided. The method includes operating a sole exhaust heat recovery mode when cooling water has a temperature less than a warm-up reference temperature to introduce all exhaust gas flowing from a DPF into the exhaust heat recovery device where the exhaust gas exchanges heat with the cooling water. Additionally, a passage through which the exhaust gas bypasses the exhaust heat recovery device is opened when the exhaust gas at a rear of the DPF has a temperature greater than the warm-up reference temperature during the sole exhaust heat recovery mode.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

An apparatus for controlling a low-pressure exhaust gas recirculation (LP-EGR) system for freezing prevention includes an intake air temperature sensor configured to measure a temperature of intake air introduced from outside, at least one engine driving sensor used to diagnose and learn a driving state of an engine, the LP-EGR system configured such that at least a portion of exhaust gas flows into the LP-EGR system as intake air, and a controller configured to perform diagnosis and learning of the driving state of the engine using the at least one engine driving sensor or to operate the LP-EGR system depending on the temperature of the intake air measured by the intake air temperature sensor when coasting conditions of a vehicle are satisfied.

An apparatus for controlling a low-pressure exhaust gas recirculation (LP-EGR) system for freezing prevention includes an intake air temperature sensor configured to measure a temperature of intake air introduced from outside, at least one engine driving sensor used to diagnose and learn a driving state of an engine, the LP-EGR system configured such that at least a portion of exhaust gas flows into the LP-EGR system as intake air, and a controller configured to perform diagnosis and learning of the driving state of the engine using the at least one engine driving sensor or to operate the LP-EGR system depending on the temperature of the intake air measured by the intake air temperature sensor when coasting conditions of a vehicle are satisfied.

The invention relates to a method for operating an internal combustion engine system (2), wherein the internal combustion engine system (2) is provided with an air intake duct (3), an exhaust gas duct (4) and an exhaust gas recirculation (EGR) system (5), wherein the EGR system (5) comprises an EGR conduit (6) that fluidly connects the exhaust duct (4) and the intake duct (3), and wherein a gas feeding device (7) configured to feed exhaust gas from the exhaust duct (4) to the intake duct (3) is arranged in the EGR conduit (6). The method is characterized in that it comprises the step of: detecting an indication of accumulated deposits of soot, hydrocarbons or other contaminants in the gas feeding device (7) by determining whether a rotational friction of a rotary member (71, 72) of the gas feeding device (7) exceeds a threshold value. The invention also relates to an internal combustion engine system (2) configured for being operated by such a method and to a vehicle (1) provided with such an engine system (2). The invention further relates to means for controlling the above method.

The invention relates to a method for operating an internal combustion engine system (2), wherein the internal combustion engine system (2) is provided with an air intake duct (3), an exhaust gas duct (4) and an exhaust gas recirculation (EGR) system (5), wherein the EGR system (5) comprises an EGR conduit (6) that fluidly connects the exhaust duct (4) and the intake duct (3), and wherein a gas feeding device (7) configured to feed exhaust gas from the exhaust duct (4) to the intake duct (3) is arranged in the EGR conduit (6). The method is characterized in that it comprises the step of: detecting an indication of accumulated deposits of soot, hydrocarbons or other contaminants in the gas feeding device (7) by determining whether a rotational friction of a rotary member (71, 72) of the gas feeding device (7) exceeds a threshold value. The invention also relates to an internal combustion engine system (2) configured for being operated by such a method and to a vehicle (1) provided with such an engine system (2). The invention further relates to means for controlling the above method.

The invention relates to a method for operating an internal combustion engine system (2), wherein the internal combustion engine system (2) is provided with an air intake duct (3), an exhaust gas duct (4) and an exhaust gas recirculation (EGR) system (5), wherein the EGR system (5) comprises an EGR conduit (6) that fluidly connects the exhaust duct (4) and the intake duct (3), and wherein a gas feeding device (7) configured to feed exhaust gas from the exhaust duct (4) to the intake duct (3) is arranged in the EGR conduit (6). The method is characterized in that it comprises the step of: providing a flushing liquid in the EGR conduit (6) upstream of the EGR gas feeding device (7) so as to flush and clean the EGR gas feeding device (7). The invention also relates to an internal combustion engine system (2) configured for being operated by such a method and to a vehicle (1) provided with such an engine system (2). The invention further relates to means for controlling the above method.

The invention relates to a method for operating an internal combustion engine system (2), wherein the internal combustion engine system (2) is provided with an air intake duct (3), an exhaust gas duct (4) and an exhaust gas recirculation (EGR) system (5), wherein the EGR system (5) comprises an EGR conduit (6) that fluidly connects the exhaust duct (4) and the intake duct (3), and wherein a gas feeding device (7) configured to feed exhaust gas from the exhaust duct (4) to the intake duct (3) is arranged in the EGR conduit (6). The method is characterized in that it comprises the step of: providing a flushing liquid in the EGR conduit (6) upstream of the EGR gas feeding device (7) so as to flush and clean the EGR gas feeding device (7). The invention also relates to an internal combustion engine system (2) configured for being operated by such a method and to a vehicle (1) provided with such an engine system (2). The invention further relates to means for controlling the above method.

An internal combustion engine includes a four-stroke combustion cylinder assembly configured for combustion of hydrogen gas within at least one combustion chamber of the combustion cylinder assembly such as to drive a crankshaft of the engine, an intake passage upstream of the cylinder assembly and an exhaust passage downstream of the cylinder assembly; a displacement compressor arranged within the intake passage, the displacement compressor being configured for compression of intake gas, an exhaust gas recirculation system configured for recirculating at least a portion of the exhaust from the exhaust passage to the displacement compressor.

Methods and systems are provided for directing the flow of recirculated exhaust gas (EGR) delivered to an EGR cooler. In one example, a method includes flowing EGR through an EGR cooler positioned in an EGR passage, the EGR cooler comprising a bypass passage, a first cooler core flow path, and a second cooler core flow path, and adjusting a valve of the EGR cooler to selectively block flow of the EGR through the bypass passage, the first cooler core flow path, and the second cooler core flow path. In this way, fouling of the EGR cooler may be reduced.