INVESTIGATION OF A NOVEL FUEL INJECTION TECHNOLOGY AIMED TO REDUCE COLD-START EMISSIONS IN SI ENGINES

摘要

A novel fuel atomization device (Nanomiser~(TM)) was evaluated under laboratory conditions with respect to its ability to reduce SI engine cold-start hydrocarbon emissions. First, comparisons between the level of atomization using the conventional, pintle-type fuel injector and the novel atomizer were carried out using flow visualization in a spray chamber and particle size distribution. The novel atomizer is capable of producing sub-micron fuel droplets, which form an ultra-fine mist with outstanding non-wetting characteristics. To capitalize on these atomization characteristics, this device was compared to a conventional fuel injector in a small, two-cylinder, SI engine under a number of operating conditions. Results show a slightly enhanced combustion quality and lean limit under warm operating conditions and a dramatic reduction in unbumed HC emission under cold operating conditions, with cold emissions with the Nanomiser~(TM) matching those with a conventional injector under fully warm conditions.