A supercharger and a turbocharger are provided, as well as a load sensor detecting a traction load of a trailer towed by a semi-trailer and being arranged in a coupler. A combined supercharging and turbocharging is performed by the supercharger and the turbocharger when the traction load is heavier than a previously defined traction determination value. Only supercharging is performed by the turbocharger when the traction load is not more than the traction determination value.

A supercharger and a turbocharger are provided, as well as a load sensor detecting a traction load of a trailer towed by a semi-trailer and being arranged in a coupler. A combined supercharging and turbocharging is performed by the supercharger and the turbocharger when the traction load is heavier than a previously defined traction determination value. Only supercharging is performed by the turbocharger when the traction load is not more than the traction determination value.

A system and methods are described for a turbocharged engine, comprising powering the engine using a first operating cylinder, supplementing the power using a second switchable cylinder, deactivating the second switchable cylinder responsive to a load below a first threshold, and closing a first shut-off valve downstream of a compressor during the partial deactivation to prevent a first turbocharger from imparting a delivery action into a second compressor during the partial deactivation. Embodiments are further described wherein a bypass line in a second exhaust line further serves as a short-circuit line to prevent the second compressor from imparting a delivery action against the closed first shut-off valve. A variable valve timing is then included to further optimize the combustion process during the partial deactivation.

A system and methods are described for a turbocharged engine, comprising powering the engine using a first operating cylinder, supplementing the power using a second switchable cylinder, deactivating the second switchable cylinder responsive to a load below a first threshold, and closing a first shut-off valve downstream of a compressor during the partial deactivation to prevent a first turbocharger from imparting a delivery action into a second compressor during the partial deactivation. Embodiments are further described wherein a bypass line in a second exhaust line further serves as a short-circuit line to prevent the second compressor from imparting a delivery action against the closed first shut-off valve. A variable valve timing is then included to further optimize the combustion process during the partial deactivation.

An engine system having donor cylinders and non-donor cylinders is disclosed. The engine system may have a first intake manifold configured to distribute air into the non-donor cylinders, and a second intake manifold configured to distribute air into the donor cylinders. The engine system may also have a first exhaust manifold configured to discharge exhaust from the non-donor cylinders to the atmosphere, and a second exhaust manifold separate from the first exhaust manifold and configured to recirculate exhaust from the donor cylinders to the first intake manifold. The engine system may further have an orifice disposed in between the first intake manifold and the second intake manifold. The orifice may be configured to regulate a flow rate of fluid flowing from the first intake manifold to the second intake manifold. The engine system may further have a controller configured to selectively control the orifice in response to a desired exhaust gas recirculation operating condition.

An engine system having donor cylinders and non-donor cylinders is disclosed. The engine system may have a first intake manifold configured to distribute air into the non-donor cylinders, and a second intake manifold configured to distribute air into the donor cylinders. The engine system may also have a first exhaust manifold configured to discharge exhaust from the non-donor cylinders to the atmosphere, and a second exhaust manifold separate from the first exhaust manifold and configured to recirculate exhaust from the donor cylinders to the first intake manifold. The engine system may further have an orifice disposed in between the first intake manifold and the second intake manifold. The orifice may be configured to regulate a flow rate of fluid flowing from the first intake manifold to the second intake manifold. The engine system may further have a controller configured to selectively control the orifice in response to a desired exhaust gas recirculation operating condition.

Various systems and methods are provided for exhaust gas recirculation. In one example, an exhaust gas recirculation (EGR) system includes an EGR passage coupling an engine exhaust system to an engine intake system, a first EGR cooler positioned in the EGR passage, the first EGR cooler configured to cool EGR with a first fluid, and a second EGR cooler positioned in the EGR passage downstream of the first EGR cooler, the second EGR cooler configured to cool EGR with a second fluid.

Various systems and methods are provided for exhaust gas recirculation. In one example, an exhaust gas recirculation (EGR) system includes an EGR passage coupling an engine exhaust system to an engine intake system, a first EGR cooler positioned in the EGR passage, the first EGR cooler configured to cool EGR with a first fluid, and a second EGR cooler positioned in the EGR passage downstream of the first EGR cooler, the second EGR cooler configured to cool EGR with a second fluid.

An air handling arrangement in a two-stroke cycle, opposed-piston engine with uniflow scavenging and constructed for heavy-duty operation includes sequentially arranged turbochargers in series with a supercharger. In some aspects, the air handling system is equipped with an EGR channel.

An air handling arrangement in a two-stroke cycle, opposed-piston engine with uniflow scavenging and constructed for heavy-duty operation includes sequentially arranged turbochargers in series with a supercharger. In some aspects, the air handling system is equipped with an EGR channel.