A control device for diesel engine controls a diesel engine with a turbo charger that coaxially joins an intake compressor and an exhaust turbine, and drives the intake compressor with energy of exhaust gas which flows into the exhaust turbine to pressurize intake air, and a fresh air/secondary air supply device that supplies fresh air or secondary air to an exhaust passage upstream of the exhaust turbine. The control device for diesel engine includes a gas flow stagnation region determination means that determines whether engine operation conditions or a state of the turbo charger are/is in a gas flow stagnation region, and a fresh air/secondary air supply means that supplies fresh air or secondary air to the exhaust passage upstream of the exhaust turbine by the fresh air/secondary air supply device when the engine operation conditions or the state of the turbo charger are/is in a gas flow stagnation region.

An engine control device capable of reducing or eliminating dew condensation in an exhaust return pipe and the like is provided. A control device according to the present invention controls an engine including an exhaust gas return mechanism that returns exhaust gas from an exhaust pipe to an intake pipe, and having a compressor in the intake pipe. The control device controls the exhaust gas return mechanism based on a pressure and on a humidity in the intake pipe.

A control device for an internal combustion engine adjusts the flow rate ratio between an amount of exhaust gas flowing to an exhaust gas recirculation cooler and an amount of exhaust gas flowing to a bypass passage, which bypasses the exhaust gas recirculation cooler, such that the amount of exhaust gas flowing to the exhaust gas recirculation cooler becomes zero during (i) a predetermined period from a point in time at which the exhaust gas recirculation operation shifts to execution, (ii) a period in which fuel cut is performed and the bed temperature of a catalyst is lower than a predetermined overheat temperature, or (iii) a period in which the flow rate of refrigerant flowing to the exhaust gas recirculation cooler is lower than a predetermined flow rate and the temperature of the refrigerant is lower than a predetermined first temperature.

A control device for an internal combustion engine adjusts the flow rate ratio between an amount of exhaust gas flowing to an exhaust gas recirculation cooler and an amount of exhaust gas flowing to a bypass passage, which bypasses the exhaust gas recirculation cooler, such that the amount of exhaust gas flowing to the exhaust gas recirculation cooler becomes zero during (i) a predetermined period from a point in time at which the exhaust gas recirculation operation shifts to execution, (ii) a period in which fuel cut is performed and the bed temperature of a catalyst is lower than a predetermined overheat temperature, or (iii) a period in which the flow rate of refrigerant flowing to the exhaust gas recirculation cooler is lower than a predetermined flow rate and the temperature of the refrigerant is lower than a predetermined first temperature.

An internal combustion engine includes an air intake system in communication with a plurality of cylinders. An exhaust system is in communication with the plurality of cylinders. An EGR passage is in communication with the exhaust system and the air intake system. The EGR passage includes an EGR cooler with an EGR inlet end with a passage having a first portion extending in one direction in an assembled condition toward an intermediate section. The passage includes a second portion extending in an opposite direction from the intermediate section toward an EGR outlet end. A first cooler matrix is disposed in the first portion and a second, optional, cooler matrix disposed in the second portion. A thermally separated bypass channel is provided to allow a fast warm-up and guarantee the lowest possible pressure drop. The EGR cooler shape allows a compact packaging around the bypass pipe.

An internal combustion engine includes an air intake system in communication with a plurality of cylinders. An exhaust system is in communication with the plurality of cylinders. An EGR passage is in communication with the exhaust system and the air intake system. The EGR passage includes an EGR cooler with an EGR inlet end with a passage having a first portion extending in one direction in an assembled condition toward an intermediate section. The passage includes a second portion extending in an opposite direction from the intermediate section toward an EGR outlet end. A first cooler matrix is disposed in the first portion and a second, optional, cooler matrix disposed in the second portion. A thermally separated bypass channel is provided to allow a fast warm-up and guarantee the lowest possible pressure drop. The EGR cooler shape allows a compact packaging around the bypass pipe.

A cooling system of a motor vehicle may include a coolant circuit including an exhaust-gas recirculation path and an exhaust-gas recirculation cooler arranged therein. A pressure detection device may be provided for detecting a coolant pressure in the coolant circuit. An actuating device may be connected communicatively to the pressure deduction device. A valve device may be connected communicatively to the actuating device and configured to control an exhaust-gas stream passing into the cooler. The actuating device may be configured to at least partially close the valve device and reduce the exhaust-gas stream flowing to the cooler in response to the pressure detection device detecting a predefined pressure drop.

A cooling system of a motor vehicle may include a coolant circuit including an exhaust-gas recirculation path and an exhaust-gas recirculation cooler arranged therein. A pressure detection device may be provided for detecting a coolant pressure in the coolant circuit. An actuating device may be connected communicatively to the pressure deduction device. A valve device may be connected communicatively to the actuating device and configured to control an exhaust-gas stream passing into the cooler. The actuating device may be configured to at least partially close the valve device and reduce the exhaust-gas stream flowing to the cooler in response to the pressure detection device detecting a predefined pressure drop.

Methods and systems are provided for exhaust gas heat recovery and exhaust gas recirculation (EGR) cooling using a single split heat exchanger. Exhaust heat from each of a first portion of exhaust routed to the intake manifold as EGR and a second portion of exhaust diverted via a bypass passage for exhaust heat recovery may be transferred to a coolant flowing through the heat exchanger. The direction of coolant flow via the heat exchanger may be adjusted based on the coolant temperature.

A dual core exhaust gas recirculation cooler includes a cooler housing having an EGR inlet, first and second EGR outlets, a cooling circuit extending from a coolant inlet through the cooler housing to a coolant outlet, a first EGR circuit core extending from the EGR inlet to the first EGR outlet, and a second EGR circuit core extending to the second EGR outlet from the EGR inlet or the first EGR outlet. A first EGR valve is configured to selectively couple the first EGR circuit core to a return passageway. A second EGR valve is configured to selectively couple the second EGR circuit core to the return passageway. The EGR valves are configured to selectively flow exhaust gas through the cooler housing within either the first EGR circuit core only or within both the first EGR circuit core and the second EGR circuit core.