2024-03-29T04:45:24Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/473892022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Effect of two-stage injection on unburned hydrocarbon and carbon monoxide emissions in smokeless low-temperature diesel combustion with ultra-high exhaust gas recirculationLi, TieSuzuki, MasaruOgawa, HideyukiDiesel EngineLow Temperature Combustion (LTC)Exhaust Gas Recirculation (EGR)Two-Stage InjectionUnburned HydrocarbonCarbon Monoxide533The unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions from smokeless low temperature diesel combustion (LTC) with ultra-high exhaust gas recirculation (EGR) can be attributed to lowered combustion temperatures as well as to under-mixing of fuel-rich mixture along the combustion chamber walls, overly-mixed fuel-lean mixture at the spray tails, and fuel missing the piston bowl and entering the squish zones. Two-stage injection has the potential to reduce UHC and CO emissions through decreasing the ratios of these mixtures. This study investigates the effects of two-stage fuel injection by varying the dwell between the two injections as well as the fuel quantity in each injection on the UHC and CO emissions, experimentally with a single cylinder diesel engine. With the optimized dwell and injection ratio, two-stage injection can reduce the UHC and CO emissions, but these emissions are still at high levels in the ultra-high EGR smokeless LTC regime. Computational fluid dynamics simulations of the in-cylinder spray and mixture formation processes showed that with the two-stage injection, over-rich mixture in the squish zones can be significantly avoided but the over-lean mixtures at center of the combustion chamber are little reduced, and these would likely be a significant source of UHC and CO emissions.Sage PublicationsJournal Articleapplication/pdfhttp://hdl.handle.net/2115/47389https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/47389/3/IJER11-5_345-354.pdf1468-08742041-3149International Journal of Engine Research1153453542010-10-01enginfo:doi/10.1243/14680874JER585The final, definitive version of this paper has been published in International Journal of Engine Research, 11(5), Oct. 2010 by SAGE Publications Ltd, All rights reserved. © Institution of Mechanical Engineersauthor