An engine system includes an engine, an intake line, an exhaust line, a turbocharger, a water-cooled intercooler, a high-pressure Exhaust Gas Recirculation (EGR) system which includes a high-pressure EGR line, a high-pressure EGR cooler, and a high-pressure EGR valve, a low-pressure EGR system which includes a low-pressure EGR line, and a low-pressure EGR cooler, a radiator which cools the coolant, a low-pressure EGR cooling line, an intercooler cooling line, a low-pressure EGR cooling valve, an intercooler cooling valve, an electric water pump, a driving information detector which detects driving information of a vehicle including an outside air temperature, a temperature of the intake gas supplied to the engine and a coolant temperature, and a controller which controls the low-pressure EGR cooling valve, the intercooler cooling valve, the high-pressure EGR valve and the electric water pump based on the driving information detected by the driving information detector.

An engine system includes an engine, an intake line, an exhaust line, a turbocharger, a water-cooled intercooler, a high-pressure Exhaust Gas Recirculation (EGR) system which includes a high-pressure EGR line, a high-pressure EGR cooler, and a high-pressure EGR valve, a low-pressure EGR system which includes a low-pressure EGR line, and a low-pressure EGR cooler, a radiator which cools the coolant, a low-pressure EGR cooling line, an intercooler cooling line, a low-pressure EGR cooling valve, an intercooler cooling valve, an electric water pump, a driving information detector which detects driving information of a vehicle including an outside air temperature, a temperature of the intake gas supplied to the engine and a coolant temperature, and a controller which controls the low-pressure EGR cooling valve, the intercooler cooling valve, the high-pressure EGR valve and the electric water pump based on the driving information detected by the driving information detector.

In a lean-burn engine equipped with a turbocharger, a responsiveness of a super-charging pressure in a lean region is enhanced by control of a valve timing of an exhaust valve while a combustion state is restrained from varying. A variable valve mechanism that can change an opening timing of the exhaust valve while keeping a closing timing of the exhaust valve constant, is included in the lean-burn engine. When a target operation point is located in the lean region, and when an actual supercharging pressure is lower than a target supercharging pressure, supercharging pressure increasing control that advances the opening timing while keeping the closing timing constant is executed by operating the variable valve mechanism.

A control apparatus for an internal combustion engine is provided. The control apparatus includes a turbocharger, a bypass passage, a wastegate valve, a catalyst device and a controller. The controller sets the wastegate valve to a closed state in a case where a warm-up execution condition is established, and performs A/F oscillation for increasing or decreasing the fuel injection amount so that lean combustion and rich combustion are alternately performed in a case where the temperature in the exhaust passage upstream of the turbocharger is beyond a predetermined reference value.

The invention relates to a method and to a device for adjusting a charging pressure in an internal combustion engine by means of a pressure-wave supercharger, wherein the pressure-wave supercharger has a cell rotor, which passes through at least two compression cycles per revolution, wherein a high-pressure exhaust-gas flow is divided into a first and a second high-pressure exhaust-gas partial flow, wherein a fresh-air flow and the first high-pressure exhaust-gas partial flow are fed to the cell rotor and a first compressed fresh-air flow and a low-pressure exhaust-gas flow are led away from the cell rotor in the first compression cycle, and wherein the fresh-air flow and the second high-pressure exhaust-gas partial flow are fed to the cell rotor and a second compressed fresh-air flow and the low-pressure exhaust-gas flow are led away from the cell rotor in the second compression cycle, wherein the first and the second compressed fresh-air flow are combined into a charge air, and wherein the charge air is fed to the internal combustion engine, wherein the second high-pressure exhaust-gas partial flow is controlled in order to control the charging pressure of the charge air in such a way, and wherein the second compressed fresh-air flow is led through a check valve before the first and the second compressed fresh-air flow are combined into the charge air.

Methods and systems are provided for controlling a boosted engine system, having a turbocharger and a charge air cooler, to limit overheating of a compressor outlet. In one example, a method includes predicting an engine torque profile based on current and future engine operating conditions. The method then models a compressor outlet temperature profile and reduces engine torque output to limit overheating of the compressor outlet.

A turbocharger system for simultaneously improving a fuel efficiency and obtaining a satisfactory hill start performance due to a downsized engine. The system includes an electric assist turbocharger which includes a turbine disposed in an exhaust passage of an engine and driven by exhaust gas, a compressor disposed in an intake passage and driven by a rotational torque of the turbine, and an electric motor assisting a driving force of the compressor and an electric motor control unit which drives the electric motor when detecting a start operation at a sloping road.

A turbocharger system for simultaneously improving a fuel efficiency and obtaining a satisfactory hill start performance due to a downsized engine. The system includes an electric assist turbocharger which includes a turbine disposed in an exhaust passage of an engine and driven by exhaust gas, a compressor disposed in an intake passage and driven by a rotational torque of the turbine, and an electric motor assisting a driving force of the compressor and an electric motor control unit which drives the electric motor when detecting a start operation at a sloping road.

Various methods and systems are provided for controlling air flow in a two-stage turbocharger. In one example, an engine method comprises adjusting one or more exhaust gas recirculation valves to maintain a first turbocharger within a first air flow range, and adjusting a turbocharger bypass valve to maintain a second turbocharger within a second air flow range.

Various methods and systems are provided for controlling air flow in a two-stage turbocharger. In one example, an engine method comprises adjusting one or more exhaust gas recirculation valves to maintain a first turbocharger within a first air flow range, and adjusting a turbocharger bypass valve to maintain a second turbocharger within a second air flow range.