A supercharger system for an engine having a turbocharger is provided. The supercharger system includes a supercharger driver and an air inlet. The supercharger system also includes a supercharger compressor mechanically coupled to the supercharger driver. The supercharger compressor includes a supercharger compressor inlet and a supercharger compressor outlet. The supercharger compressor inlet is in fluid communication with the air inlet. The supercharger compressor outlet is in fluid communication with a turbine inlet associated with the turbocharger.

Methods and systems are provided for reducing turbo lag by directing intake air from an intake manifold to an exhaust manifold. The intake air may be directed via an EGR passage by opening an EGR valve or by may be directed via engine cylinders by increasing positive valve overlap. Amounts of air directed via external EGR and air directed via positive valve overlap are based on engine operating conditions.

Methods and systems are provided for reducing turbo lag by directing intake air from an intake manifold to an exhaust manifold. The intake air may be directed via an EGR passage by opening an EGR valve or by may be directed via engine cylinders by increasing positive valve overlap. Amounts of air directed via external EGR and air directed via positive valve overlap are based on engine operating conditions.

A turbocharged engine system with electric compressor arranged to inject a compressed fluid into the exhaust subsystem upstream of the turbine of the turbocharger such that, in use, the compressed fluid injected by the electric compressor into the exhaust subsystem maintains the speed of or accelerates the turbine, thereby maintaining or increasing the boost pressure supplied to the turbocharged internal combustion engine. A method of controlling the boost pressure supplied to an internal combustion engine by a turbocharger, said method comprising the steps of: producing a stream of compressed fluid; injecting the stream of compressed fluid into an exhaust stream of the internal combustion engine to produce a pressure-boosted exhaust stream; and controlling the speed of a turbine of the turbocharger using the pressure-boosted exhaust stream to control the boost pressure supplied to the internal combustion engine.

A turbocharged engine system with electric compressor arranged to inject a compressed fluid into the exhaust subsystem upstream of the turbine of the turbocharger such that, in use, the compressed fluid injected by the electric compressor into the exhaust subsystem maintains the speed of or accelerates the turbine, thereby maintaining or increasing the boost pressure supplied to the turbocharged internal combustion engine. A method of controlling the boost pressure supplied to an internal combustion engine by a turbocharger, said method comprising the steps of: producing a stream of compressed fluid; injecting the stream of compressed fluid into an exhaust stream of the internal combustion engine to produce a pressure-boosted exhaust stream; and controlling the speed of a turbine of the turbocharger using the pressure-boosted exhaust stream to control the boost pressure supplied to the internal combustion engine.

A hydrogen fueled powerplant including an internal combustion engine that drives a motor-generator, and has a two-stage turbocharger, for an aircraft. A control system controls the operation of the motor-generator to maintain the engine at a speed selected based on controlling the engine equivalence ratio. The control system controls an afterburner, an intercooler and an aftercooler to maximize powerplant efficiency. The afterburner also adds power to the turbochargers during high-altitude restarts. The turbochargers also include motor-generators that extract excess power from the exhaust.

A hydrogen fueled powerplant including an internal combustion engine that drives a motor-generator, and has a two-stage turbocharger, for an aircraft. A control system controls the operation of the motor-generator to maintain the engine at a speed selected based on controlling the engine equivalence ratio. The control system controls an afterburner, an intercooler and an aftercooler to maximize powerplant efficiency. The afterburner also adds power to the turbochargers during high-altitude restarts. The turbochargers also include motor-generators that extract excess power from the exhaust.

An engine system having an ERG apparatus may include an engine including a plurality of combustion chambers generating a driving torque by combustion of a fuel; an intake line inflowing an intake gas supplied to the combustion chamber; an exhaust line flowing an exhaust gas exhausted from the combustion chamber; a turbocharger including a turbine provided at the exhaust line and rotated by the exhaust gas exhausted from the combustion chamber and a compressor provided at the intake line, rotated in connection with the turbine, and compressing external air; and an EGR apparatus including a recirculation line branched from the exhaust line and joined to the intake line, a flow rate controller mounted at the recirculation line and measuring and controlling an amount of recirculation gas, and a pressure sensor mounted at the recirculation line to measure a pressure of the recirculation gas.

An engine system having an ERG apparatus may include an engine including a plurality of combustion chambers generating a driving torque by combustion of a fuel; an intake line inflowing an intake gas supplied to the combustion chamber; an exhaust line flowing an exhaust gas exhausted from the combustion chamber; a turbocharger including a turbine provided at the exhaust line and rotated by the exhaust gas exhausted from the combustion chamber and a compressor provided at the intake line, rotated in connection with the turbine, and compressing external air; and an EGR apparatus including a recirculation line branched from the exhaust line and joined to the intake line, a flow rate controller mounted at the recirculation line and measuring and controlling an amount of recirculation gas, and a pressure sensor mounted at the recirculation line to measure a pressure of the recirculation gas.

Methods and systems are provided for an automatic branch communication valve. In one example, a method includes rotating the valve to a second position in response to a non-electrical actuation of the valve.