Application of hybrid EGR systems to turbocharged GDI engines

Roth, David B.; Sauerstein, Rolf; Becker, Michael; Meilinger, Rob

doi:10.1007/bf03227986

Cited by 3 publications

(1 citation statement)

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“…From the literature, 54 the HP EGR system had the advantage of a minimum volume between the EGR control valve and the intake valves, which is beneficial for controlling the EGR rate during engine load transitions. In contrast, the LP EGR prevailed over the HP EGR on the exhaust gas temperature controllability, and LP EGR is more perfectly cylinder-to-cylinder distributed.…”

Section: Strategies For Optimizing the Gas Exchange Processmentioning

confidence: 99%

Novel approaches to improve the gas exchange process of downsized turbocharged spark-ignition engines: A review

Akehurst

Brace

2015

International Journal of Engine Research

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Engine downsizing, which is the use of a smaller engine that provides the power of a larger engine, is now considered a mega-trend for the internal combustion engine market. It is usually achieved using one or more boosting devices including a supercharger or a turbocharger. Although supercharging is beneficial for engine's transient response, turbocharging technology is more widely adopted considering its advantages in fuel efficiency. Compared to turbocharged compression ignition engines, turbocharged spark-ignition engines tend to be more challenging with respect to the gas exchange process mainly due to their higher pumping loss, the need for throttling and the fact that spark-ignition engines demand more controllability due to the mitigation of knock, particularly with regard to minimizing trapped residuals. These challenges encourage the entire gas exchange process of turbocharged spark-ignition engines to be regarded as a complete air management system instead of just looking at the boosting system in isolation. In addition, more research emphasis should be focused on novel approaches to improve the gas exchange process of downsized turbocharged spark-ignition engines because the refinement of the conventional technologies cannot provide continuous gains indefinitely and only innovative concept may improve the engine performance to meet the fuel efficiency target and the more stringent emission regulation in the future. This article will first briefly review knowledge of the current state of the art technologies that are in production as opposed to approaches that are currently only being investigated at a research level. Next, more novel methods of the gas exchange process are introduced to identify the improved synergies between the engine and the boosting machine. The major findings to improve the gas exchange process that emerge from this review comprise four aspects (depending on the location where the novel technologies are implemented) which are as follows: charge air pressurization/de-pressurization improvement, combustion efficiency enhancement within the chamber, valve event-associated development and exhaust system optimization. Although the interaction between these technologies on different aspects of the gas exchange process was found to be highly complex, the optimization or the combination of these technologies is anticipated to further improve a downsized turbocharged spark-ignition engine's performance.

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Section: Strategies For Optimizing the Gas Exchange Processmentioning

confidence: 99%