The invention concerns a method for controlling a compression release brake mechanism in an combustion engine comprising an air inlet system and an exhaust manifold connected to a turbocharger provided with a variable turbine geometry (VTG) turbine, said exhaust manifold further comprising an exhaust gas recirculation (EGR) channel for recirculation of exhaust gas towards the air inlet system, wherein said turbine is further connected to a back pressure valve (BPV) provided in an exhaust channel, the method comprising determining a desired exhaust manifold gas pressure level on the basis of a measured engine speed and a desired braking torque; continuously monitoring a set of control parameters, including at least two of cylinder pressure, exhaust manifold pressure, turbine speed and turbine expansion ratio; controlling said BPV and said VTG by said control parameters, to drive one of the control parameters to a set maximum level; and controlling the EGR by said control parameters in a closed loop to allow exhaust gas to recirculate towards the air inlet system while driving a second of the set of control parameters to a set maximum level.

A turbine is provided with: a turbine wheel configured to rotate about an axis O1; a turbine housing accommodating the turbine wheel and defining an annular nozzle passage on the outer peripheral side of the turbine wheel; and a plurality of low solidity nozzle vanes 6 arranged in the nozzle passage at an interval in the circumferential direction. Circumferentially adjacent low solidity nozzle vanes 6 are disposed at different radial positions in a connection position of each of the low solidity nozzle vanes 6 with a hub-side wall surface of the hub-side wall surface and a shroud-side wall surface which define the nozzle passage.

A variable capacity turbocharger includes: a nozzle flow path which allows a gas to pass from a scroll flow path toward a turbine impeller; a shroud side ring and a hub side ring which face each other in a rotation axis direction of the turbine impeller and form a nozzle flow path therebetween; a bearing hole which is provided in the shroud side ring; a bearing hole which is provided in the hub side ring; and a nozzle vane which is disposed in the nozzle flow path and is supported by both bearing holes, wherein a center axis line of the bearing hole is located on the inside in a radial direction in relation to a center axis line of the bearing hole at a room temperature and the center axis line is located on the outside in the radial direction in relation to the center axis line when a predetermined temperature difference is generated between the shroud side ring and the hub side ring during operation.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

An engine system includes an internal combustion engine, a fuel cell system, a first turbocharger and a second turbocharger. The internal combustion engine has an intake passage, and a first exhaust passage fluidly connected to the first set of combustion chambers. The first turbocharger has a first compressor and a first turbine. The second turbocharger has a second compressor and a second turbine, the second compressor connected in series with the first compressor, and the second turbine being in fluid communication with the second exhaust passage. The first and second turbines are connected in parallel such that the first turbine only receives exhaust flow from the fuel cell system, and the second turbine only receives exhaust flow from the internal combustion engine.

An engine system includes an internal combustion engine, a fuel cell system, a first turbocharger and a second turbocharger. The internal combustion engine has an intake passage, and a first exhaust passage fluidly connected to the first set of combustion chambers. The first turbocharger has a first compressor and a first turbine. The second turbocharger has a second compressor and a second turbine, the second compressor connected in series with the first compressor, and the second turbine being in fluid communication with the second exhaust passage. The first and second turbines are connected in parallel such that the first turbine only receives exhaust flow from the fuel cell system, and the second turbine only receives exhaust flow from the internal combustion engine.

In one aspect, a method for controlling an internal combustion engine system including an exhaust gas recirculation (EGR) valve and a variable-geometry turbocharger (VGT) having a compressor and a turbine includes receiving a plurality of requests for the internal combustion engine system. The method also includes predicting a plurality of expected states of the internal combustion engine system based on the plurality of requests and generating sets of candidate control points for actuating the EGR valve and the VGT based on the plurality of expected states. The method further includes selecting a set of candidate control points that avoids a surge condition of the compressor and based on the selected set of candidate control points, generating commands for actuating the EGR valve and the VGT.

In one aspect, a method for controlling an internal combustion engine system including an exhaust gas recirculation (EGR) valve and a variable-geometry turbocharger (VGT) having a compressor and a turbine includes receiving a plurality of requests for the internal combustion engine system. The method also includes predicting a plurality of expected states of the internal combustion engine system based on the plurality of requests and generating sets of candidate control points for actuating the EGR valve and the VGT based on the plurality of expected states. The method further includes selecting a set of candidate control points that avoids a surge condition of the compressor and based on the selected set of candidate control points, generating commands for actuating the EGR valve and the VGT.

Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.