GDI Very High Pressure Injector for High Compression Gasoline Engine

Authors

G. Signorelli PhD, A. Cavani MSc, M. Petrone MSc, S. Petrecchia MSc, Marelli Europe, Bologna; M. Nishida MSc, Mazda Motor Corporation, Hiroshima, Japan:

Year

2021

Print Info

Production/Publication ÖVK

Summary

Although electric drive technology has demonstrated to be effective in reducing CO₂ emissions generated by vehicles, there are still technical issues to be resolved before a significant part of the current fleet of vehicles in circulation can be replaced by Battery Electric Vehicles (BEVs). Therefore, in the near future improving the thermal efficiency of the internal combustion engine of hybrid vehicles is a key step in the process of reducing CO₂ emissions. Making this change basically means improving the thermal efficiency of an internal combustion engine by increasing the compression ratio and generating a higher specific heat ratio by injecting a leaner gasoline mixture into the combustion chamber. Appropriately controlling the distribution of the mixture’s fuel concentration and injecting fuel to a knock occurring position are well known factors that lead to stable lean combustion, preventing knock in engines at a high compression ratio. However, up to now it has not been possible to achieve stable effects with conventional gasoline injector technology, as injection systems have limitations on fuel pressure, injected quantities and accuracy. These technical limitations were well known, and not resolving them meant generating soot and NOx. Marelli and Mazda Motor Corporation have developed a new gasoline injection system where the core cutting-edge technology is the fuel injector. It can operate at a fuel pressure over 70 MPa with seamless injected quantities from 1mm3 adopting more than five-stage injections with 500 µsec dwell time. This paper describes the technology and the characteristics of the injector and its effects on the improvement of engine performance.

Number of pages

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