摘要:
Various methods and systems are provided for controlling air flow in a two-stage turbocharger. In one example, an engine method comprises adjusting one or more exhaust gas recirculation valves to maintain a first turbocharger within a first air flow range, and adjusting a turbocharger bypass valve to maintain a second turbocharger within a second air flow range.
摘要:
An exemplary turbocharger system for an internal combustion engine is provided. The turbocharger system includes a first turbine and a second turbine. The first turbine is in fluid communication with the internal combustion engine. The first turbine receives a first portion exhaust gas discharged from the internal combustion engine and provides a first turbine exhaust gas. The second turbine is in fluid communication with the first turbine via an inter-stage channel. The inter-stage channel transports the first turbine exhaust gas from the first turbine to the second turbine. The inter-stage channel is in thermal connection with an exhaust gas recirculation channel defined between an inlet and an outlet of the internal combustion engine. The first turbine exhaust gas flowing through the inter-stage channel is capable of being heated by a second portion exhaust gas discharged from the internal combustion engine and flowing through the exhaust gas recirculation channel.
摘要:
A diffuser (30) for a centrifugal compressor (60) having a flow slot (34) formed between the leading edge portion (36) of a diffuser vane (32) and an adjoining diffuser wall (70) for the passage of working fluid (67) over the vane from the pressure side ((40) to the suction side (42) of the vane. The portion (38) of the working fluid passing over the vane is injected into the flow boundary region (43), thereby minimizing the growth of a flow separation zone (58) along the suction side.
摘要:
Compressor wheel and techniques for manufacturing such a wheel are provided. The wheel may include a hub with a counterbore internally treated to impart residual compressive stresses for enhanced endurance to stress-induced fatigue. The surface treatment allows extending the counterbore relatively closer to a plane of typical maximum stress of the wheel. This design flexibility advantageously allows avoiding or reducing overhang of the compressor wheel, thereby improving rotor dynamics and reducing the axial length of the hub, and the overall foot print of the compressor wheel.
摘要:
Various methods and systems are provided for lowering exhaust gas temperature. In one embodiment, a method comprises increasing an air-to-fuel ratio of an engine in response to an exhaust gas temperature exceeding a threshold temperature value to lower the exhaust gas temperature to a temperature below the threshold temperature value.
摘要:
A turbocharger includes a compressor, a turbine, a shaft coupling the compressor to the turbine, and a turbo casing configured to improve pressure recovery and reduce energy loss from exhaust flow. In one embodiment, the turbo casing may include a geometry configured to improve exhaust flow towards an exhaust outlet. The turbo casing may include a torus shaped chamber having a cross-sectional area that progressively increases in an annular direction of the flow towards the exhaust outlet.
摘要:
A turbine system for a multistage turbocharger and a method for utilizing the same are disclosed. The turbine system includes a high pressure turbine having an inlet for receiving a flow of fluid, and an outlet for passing the flow on extraction of work from the high pressure turbine. The system further includes a low pressure turbine, having an inlet for receiving a flow of fluid from the high pressure turbine. A diffuser connects the outlet of the high pressure turbine and the inlet of the low pressure turbine. The system also includes a bypass channel for bypassing a portion of the flow around the high pressure turbine, from upstream of the high pressure turbine to downstream of the high pressure turbine. The system includes an injector to input the bypass flow in the diffuser in a manner to reduce flow separation in the diffuser.
摘要:
Various methods and systems are provided for lowering exhaust gas temperature. In one embodiment, a method comprises increasing an air-to-fuel ratio of an engine in response to an exhaust gas temperature exceeding a threshold temperature value to lower the exhaust gas temperature to a temperature below the threshold temperature value.
摘要:
An exemplary turbocharger system for an internal combustion engine is provided. The turbocharger system includes a first turbine and a second turbine. The first turbine is in fluid communication with the internal combustion engine. The first turbine receives a first portion exhaust gas discharged from the internal combustion engine and provides a first turbine exhaust gas. The second turbine is in fluid communication with the first turbine via an inter-stage channel. The inter-stage channel transports the first turbine exhaust gas from the first turbine to the second turbine. The inter-stage channel is in thermal connection with an exhaust gas recirculation channel defined between an inlet and an outlet of the internal combustion engine. The first turbine exhaust gas flowing through the inter-stage channel is capable of being heated by a second portion exhaust gas discharged from the internal combustion engine and flowing through the exhaust gas recirculation channel.
摘要:
A turbocharger system, in certain embodiments, includes a compressor, a turbine, a shaft of common diameter coupling the compressor to the turbine, and a first fluid film bearing disposed about the shaft at a compressor end portion of the shaft. The system also includes a second fluid film fixed pad bearing disposed about the shaft at a turbine end portion of the shaft, wherein the first and second fluid film fixed pad bearings have different clearance ratios, effective lengths, or both, relative to one another. The system, in some embodiments, includes a compressor fluid film fixed pad bearing and a turbine fluid film fixed pad bearing, wherein the compressor and turbine fluid film fixed pad bearings have different clearance ratios and effective lengths, relative to one another.