open access

https://hdl.handle.net/2115/47389

Effect of two-stage injection on unburned hydrocarbon and carbon monoxide emissions in smokeless low-temperature diesel combustion with ultra-high exhaust gas recirculation

英語

Carbon Monoxide

2010-10-01

Sage Publications

International Journal of Engine Research

11(5)

345-354

The 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.

学術雑誌論文

Accepted Manuscript

The 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 Engineers

1468-0874

2041-3149