Pre-Chamber Ignition and Promising Complementary Technologies

Authors

Dipl.-Ing. Marc Sens, Dr.-Ing. Emanuel Binder, Dipl.-Ing. Paul-Benjamin Reinicke, Dipl.-Ing. Michael Riess, Dipl.-Ing. Thorsten Stappenbeck, Marcus Wöbke, MSc,
IAV GmbH, Berlin

Summary

Future passenger-car combustion engines have to realize efficiencies that are far beyond current series technology means. Peak efficiencies of 45 % and higher are repeatedly mentioned as target values. Only an optimal combination of existing and new technology elements, in a complementary way, may achieve these ambitious targets.

Pre-Chamber ignition is such a technology element. It mitigates knock significantly. Flame jets act as multiple room filling ignition spots and simultaneously increase turbulence. In contrast to a conventional spark plug, the Pre-Chamber ignition complements several fuel-saving combustion processes that decelerate combustion or lack turbulence, such as EGR or Miller cycle (EIVC).

The active Pre-Chamber increases the dilution capability of the entire combustion process beyond current limits. By providing a small quantity of both fuel and air to the Pre-Chamber, the ignition conditions inside the Pre-Chamber can be re-established – regardless whether the dilution is achieved with air or EGR. A special low-pressure injector mixes air and fuel already outside the pre-chamber reducing pollutants drastically.

Finally, the mentioned technology combinations were investigated and improved on a single-cylinder engine across the WLTC relevant map range to show a realistic fuel saving potential. The promising results lead to a feasibility study that considered especially the stable overall engine operation and the integration of the PCSP into a full-cylinder engine.

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