The disclosure relates to an exhaust gas aftertreatment system with a turbine arranged in the exhaust gas line and with a main catalytic converter arranged downstream from the turbine, wherein the exhaust gas line has a bypass line and a bypass connector, wherein the bypass line opens downstream from the turbine, wherein a main particle filter and, in the bypass line, a catalytic converter are provided, wherein the bypass valve a1) is formed as a three-way valve is and forms the bypass connector a2) the bypass valve is formed as a three-way valve and is provided at the opening b1) is positioned in the bypass line, wherein an exhaust gas flap is provided upstream from the opening in the exhaust gas line b2) the exhaust gas line is formed without exhaust gas flaps downstream from the bypass connector and upstream from the opening, and the catalytic converter has a three-way coating or the respective main catalytic converter has a DOC coating.

Various methods and systems are provided for controlling air flow through an engine by adjusting an electric turbocharger of a vehicle. In one embodiment, a system for a vehicle comprises an electric turbocharger comprising a compressor, an exhaust turbine coupled to the compressor via a shaft, and an electric machine mechanically coupled to the shaft; and a controller including a processor and instructions stored on a non-transient memory of the controller that, when executed, cause the controller to: adjust an amount of power provided to or extracted from the shaft by the electric machine based on at least one of a speed of the electric turbocharger, a cylinder pressure, and an exhaust gas temperature. By adjusting the amount of power provided to or extracted from the electric machine, the exhaust gas temperature and the speed of the electric turbocharger may be efficiently maintained within a desired operating range.

Various methods and systems are provided for controlling air flow through an engine by adjusting an electric turbocharger of a vehicle. In one embodiment, a system for a vehicle comprises an electric turbocharger comprising a compressor, an exhaust turbine coupled to the compressor via a shaft, and an electric machine mechanically coupled to the shaft; and a controller including a processor and instructions stored on a non-transient memory of the controller that, when executed, cause the controller to: adjust an amount of power provided to or extracted from the shaft by the electric machine based on at least one of a speed of the electric turbocharger, a cylinder pressure, and an exhaust gas temperature. By adjusting the amount of power provided to or extracted from the electric machine, the exhaust gas temperature and the speed of the electric turbocharger may be efficiently maintained within a desired operating range.

Turbine fracturing equipment is provided. The turbine fracturing equipment includes: a turbine engine, having an exhaust end configured to discharge exhaust gas; an exhaust pipe having a first end and a second end, the first end of the exhaust pipe being configured such that the exhaust gas discharged from the exhaust end of the turbine engine enters the exhaust pipe, and the second end of the exhaust pipe being configured to discharge the exhaust gas in the exhaust pipe; and an exhaust gas energy recovery device, the exhaust gas energy recovery device including a thermal energy recovery mechanism configured to recover thermal energy of the exhaust gas and a kinetic energy recovery mechanism configured to recover kinetic energy of the exhaust gas, at least a part of the thermal energy recovery mechanism and at least a part of the kinetic energy recovery mechanism are arranged in the exhaust pipe.

Turbine fracturing equipment is provided. The turbine fracturing equipment includes: a turbine engine, having an exhaust end configured to discharge exhaust gas; an exhaust pipe having a first end and a second end, the first end of the exhaust pipe being configured such that the exhaust gas discharged from the exhaust end of the turbine engine enters the exhaust pipe, and the second end of the exhaust pipe being configured to discharge the exhaust gas in the exhaust pipe; and an exhaust gas energy recovery device, the exhaust gas energy recovery device including a thermal energy recovery mechanism configured to recover thermal energy of the exhaust gas and a kinetic energy recovery mechanism configured to recover kinetic energy of the exhaust gas, at least a part of the thermal energy recovery mechanism and at least a part of the kinetic energy recovery mechanism are arranged in the exhaust pipe.

A turbine wheel consists of a first shroud component and a second bladed disc component. The shroud component comprises a shroud structure, a hub structure and a spoke formed integrally therewith and extending between the shroud structure and the hub structure. The bladed disc component comprises a hub member having inner and outer rims, turbine blades disposed on the outer rim, and at least one receiving zone for receiving the spoke, said at least one receiving zone extending radially between the inner and outer rims. The shroud component and the bladed disc component are connected and thus provide the turbine wheel with a shrouded portion. A shrouded turbine wheel can therefore be conveniently assembled starting from at least two components. Further, these components have simplified geometries for easy manufacture, for example using a casting technique, while the overall mechanical performance of the turbine is preserved or improved.

A turbine wheel consists of a first shroud component and a second bladed disc component. The shroud component comprises a shroud structure, a hub structure and a spoke formed integrally therewith and extending between the shroud structure and the hub structure. The bladed disc component comprises a hub member having inner and outer rims, turbine blades disposed on the outer rim, and at least one receiving zone for receiving the spoke, said at least one receiving zone extending radially between the inner and outer rims. The shroud component and the bladed disc component are connected and thus provide the turbine wheel with a shrouded portion. A shrouded turbine wheel can therefore be conveniently assembled starting from at least two components. Further, these components have simplified geometries for easy manufacture, for example using a casting technique, while the overall mechanical performance of the turbine is preserved or improved.

A straddled vehicle having an engine unit supported by a vehicle body frame. The engine unit includes an engine body, a turbocharger, and an exhaust device. The exhaust device includes an exhaust pipe and a muffler that are connected to each other to form a portion of an exhaust passage, to allow the exhaust gas passed through the turbocharger to pass therethrough, and a first catalyst and a second catalyst that are arranged in this order along a direction in which the exhaust gas flows through the exhaust pipe. The exhaust pipe has an upstream end thereof connected to the turbocharger, a downstream end thereof connected to the muffler, and a corner section that is bent in at least a part thereof between a downstream end of the first catalyst and an upstream end of the second catalyst, the catalysts not being arranged in the corner section.

A bottoming cycle power system includes a turbine-generator. The turbine-generator includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander is operable to rotate the turbo-crankshaft as a flow of exhaust gas from a combustion process passes through the turbo-expander. The turbo-compressor is operable to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. An exhaust gas heat exchanger includes first and second flow paths operable to exchange heat therebetween. The first flow path is operable to receive the flow of exhaust gas from the turbo-expander prior to the exhaust gas being compressed by the turbo-compressor. The second flow path is operable to receive the flow of exhaust gas from the turbo-compressor after the exhaust gas has been compressed by the turbo-compressor.

A bottoming cycle power system includes a turbine-generator. The turbine-generator includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander is operable to rotate the turbo-crankshaft as a flow of exhaust gas from a combustion process passes through the turbo-expander. The turbo-compressor is operable to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. An exhaust gas heat exchanger includes first and second flow paths operable to exchange heat therebetween. The first flow path is operable to receive the flow of exhaust gas from the turbo-expander prior to the exhaust gas being compressed by the turbo-compressor. The second flow path is operable to receive the flow of exhaust gas from the turbo-compressor after the exhaust gas has been compressed by the turbo-compressor.