An exhaust gas recirculation system includes a first turbocharger and a second turbocharger connected in series. An outlet of a turbine of the second turbocharger is connected to an exhaust pipe. An inlet of a compressor of the second turbocharger is connected to the exhaust pipe by means of an EGR gas collection pipe, and an outlet of the compressor of the second turbocharger is connected to an intake manifold by means of a low-pressure EGR exhaust pipe. The system employs energy of exhaust gas to drive turbines of a two-stage turbocharging system, thereby increasing utilization of the exhaust gas and improving the economic efficiency of an engine. An engine is also disclosed.

An engine device including an exhaust manifold provided on an exhaust side surface which is a first side surface of a cylinder head and a two-stage turbocharger that is driven by exhaust gas discharged from the exhaust manifold. The two-stage turbocharger includes a high-pressure turbocharger coupled to the exhaust manifold and a low-pressure turbocharger coupled to the high-pressure turbocharger. The high-pressure turbocharger is arranged on a side of the exhaust manifold. The low-pressure turbocharger is arranged above the exhaust manifold. An exhaust gas outlet of the high-pressure turbocharger and an exhaust gas inlet of the low-pressure turbocharger are coupled with each other through a flexible high-pressure exhaust gas pipe.

The invention provides an internal combustion engine system (1) comprising—at least one combustor (3), and—a first expander (4) arranged to receive exhaust gases from at least one of the at least one combustor (3), and to expand and extract energy from the exhaust gases —characterized in that the system comprises a second expander (5) arranged to receive exhaust gases from the first expander (4), and to expand and extract energy from the exhaust gases.

The high pressure compressor wheel of a two stage turbocharger assembly is cooled by charge air bled from the charge air flowpath downstream of the aftercooler. A wastegate may be arranged across the high pressure stage and operated by an actuator which in turn is operable by the static or dynamic pressure of the charge air in the cooling flowpath. The cooling airflow may be blocked to open the wastegate and released or resumed to close the wastegate so that cooling air is supplied only while the high pressure compressor wheel is under load.

Methods and systems are provided for an EGR system. In one example, a system comprises a first turbocharger configured to increase an intake gas pressure and a second turbocharger configured to increase an exhaust gas pressure. The second turbocharger is dedicated to only compressing exhaust gases flowing to an intake passage.

Methods and systems are provided for an EGR system. In one example, a system comprises a first turbocharger configured to increase an intake gas pressure and a second turbocharger configured to increase an exhaust gas pressure. The second turbocharger is dedicated to only compressing exhaust gases flowing to an intake passage.

A method for maximising the total power output of a power generation system is described the method comprising providing a power generation system comprising a turbocharged prime mover and a turbogenerator system driven by a flow of exhaust fluid from the prime mover, the turbogenerator system creating a backpressure on the turbocharged prime mover, comparing a parameter of the power generation system to a threshold value of the parameter, and adjusting the turbogenerator system to vary the backpressure on the turbocharged prime mover to change the parameter to become closer to the threshold value and increase the total power output or fuel efficiency of the power generation system. An apparatus for performing the method is also described.

A low-temperature turbocompressor structural arrangement for an internal combustion engine for using energy that is available but unused during operation to cool the air supplied to the engine by supercharging. The temperature of the air compressed by the compressor is reduced by a cooling system and the air is then conveyed to a further turbine actuated by the intake air flow of the engine. The structural arrangement may be mounted in full or in part, and also each component may be fitted into existing systems.

The low-temperature turbocompressor structural arrangement for an internal combustion engine is a system for using the energy that is available but unused during operation of an internal combustion engine, for cooling the air supplied to said engine by supercharging, applicable to internal combustion engines of any type. The temperature of the air compressed by the compressor is reduced by a cooling system and the air is then conveyed to a further turbine actuated by the intake air flow of the engine, affording the benefits of enhancing engine performance levels, which may be used in order to obtain greater power or reduce consumption, since the denser air allows more fuel into the combustion chamber, achieving greater combustion, which increases the power-to-weight ratio, and the cooler air allows work at more aggressive compression and/or ignition advance ratios without problems of pre-ignition/pinking, thereby enhancing engine performance levels. The structural arrangement may be mounted in the integral form thereof or in partial forms, and also each component may be fitted into existing systems.

A system and method is provided for controlling an electric machine rotatably coupled to a rotatable shaft of an electronically-controlled one of a turbocharger and an exhaust-driven turbo supercharger fluidly coupled to an exhaust duct of an internal combustion engine. An operating temperature of a component of the engine is determined or estimated an operating temperature of a component of the engine or coupled to the engine, which is compared to a threshold temperature. The electric machine is controlled to operate as a motor in response to the determined or estimated temperature of the component being below a threshold temperature.