The research is to design a differential pumping system not only to achieve the pressure transition with a large throughput,but also to achieve a clean system without back-oil.In the paper,the pressure in differential...The research is to design a differential pumping system not only to achieve the pressure transition with a large throughput,but also to achieve a clean system without back-oil.In the paper,the pressure in differential stages is calculated;the differential pumping system design and equipment choice are introduced;the tests of Molecular/Booster Pump(MBP),a new kind of molecular-drag pump with large throughout and clean vacuum are described and the system experimental result and analysis are presented.展开更多
Driven by a demand for better fuel economy and increasingly stringent emissions regulations over a wide range of customers and applications,engine manufacturers have turned towards engine downsizing as the most potent...Driven by a demand for better fuel economy and increasingly stringent emissions regulations over a wide range of customers and applications,engine manufacturers have turned towards engine downsizing as the most potent enabler to meet these requirements.With boosting systems becoming ever more numerous as the technical solutions to complex boosting requirements of the internal combustion engine increase,it is time for an overview of available and under development boosting technologies and systems and for a discussion of their relevance to downsizing efforts.The presented analysis shows that there are no standard solutions for all the different applications as the trends indicate a rising complexity to meet with the extreme boosting requirements predicted for the remainder of the decade.These trends include variable geometry,a shift from single to two(or more)stages,extensive actuation for bypassing exhaust flows,exhaust flow regulation and pulsating exhaust energy recovery, severe electrification and an extensive effort downstream from the turbine to capture waste heat after the principal turbo- charger/supercharger system.展开更多
文摘The research is to design a differential pumping system not only to achieve the pressure transition with a large throughput,but also to achieve a clean system without back-oil.In the paper,the pressure in differential stages is calculated;the differential pumping system design and equipment choice are introduced;the tests of Molecular/Booster Pump(MBP),a new kind of molecular-drag pump with large throughout and clean vacuum are described and the system experimental result and analysis are presented.
文摘Driven by a demand for better fuel economy and increasingly stringent emissions regulations over a wide range of customers and applications,engine manufacturers have turned towards engine downsizing as the most potent enabler to meet these requirements.With boosting systems becoming ever more numerous as the technical solutions to complex boosting requirements of the internal combustion engine increase,it is time for an overview of available and under development boosting technologies and systems and for a discussion of their relevance to downsizing efforts.The presented analysis shows that there are no standard solutions for all the different applications as the trends indicate a rising complexity to meet with the extreme boosting requirements predicted for the remainder of the decade.These trends include variable geometry,a shift from single to two(or more)stages,extensive actuation for bypassing exhaust flows,exhaust flow regulation and pulsating exhaust energy recovery, severe electrification and an extensive effort downstream from the turbine to capture waste heat after the principal turbo- charger/supercharger system.
