Improvement of the Performance on the Small-Scale PCCI Engine Fuelled by Natural Gas (Fourth Report)

- Effects of internal EGR method on Engine Performance and Exhaust Emissions -

Abstract

In order to control the natural-gas PCCI combustion, the internal EGR by means of exhaust valve re-opening(EVRO) during induction stroke was applied to a single-cylinder test engine. Combustion phasing can be controlled successfully by adjusting the EGR ratio, so that improvement of thermal efficiency and the reductio in unburned exhaust-emissions can be achieved. Also, results of EVRO method have been compared to those of inteke-valve pilot-openig (IVPO) during exhaust stroke. It is shown that EVRO is more useful heat-recovery metod for PCCI combustion improvement than IVPO.