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Title: Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine

Abstract

This work explores the mechanisms by which a post injection can reduce unburned hydrocarbon (UHC) emissions in heavy-duty diesel engines operating at low-temperature combustion conditions. Post injections, small, close-coupled injections of fuel after the main injection, have been shown to reduce UHC in the authors’ previous work. In this work, we analyze optical data from laser-induced fluorescence of both CH2O and OH and use chemical reactor modeling to better understand the mechanism by which post injections reduce UHC emissions. The results indicate that post-injection efficacy, or the extent to which a post injection reduces UHC emissions, is a strong function of the cylinder pressure variation during the post injection. However, the data and analysis indicate that the pressure and temperature rise from the post injection combustion cannot solely explain the UHC reduction measured by both engine-out and optical diagnostics. In conclusion, the fluid-mechanic, thermal, and chemical interaction of the post injection with the main-injection mixture is a key part of UHC reduction; the starting action of the post jet and the subsequent entrainment of surrounding gases are likely both important processes in reducing UHC with a post injection.

Authors:
 [1];  [2];  [2]
  1. Pennsylvania State Univ., University Park, PA (United States)
  2. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
OSTI Identifier:
1326655
Alternate Identifier(s):
OSTI ID: 1334829
Report Number(s):
SAND-2015-9856M
Journal ID: ISSN 0010-2180; PII: S0010218016300748
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Accepted Manuscript
Journal Name:
Combustion and Flame
Additional Journal Information:
Journal Volume: 170; Journal Issue: C; Journal ID: ISSN 0010-2180
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
33 ADVANCED PROPULSION SYSTEMS; low-temperature combustion; unburned hydrocarbon emissions; post injections; heavy-duty diesel

Citation Formats

O'Connor, Jacqueline, Musculus, Mark P. B., and Pickett, Lyle M. Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine. United States: N. p., 2016. Web. doi:10.1016/j.combustflame.2016.03.031.
O'Connor, Jacqueline, Musculus, Mark P. B., & Pickett, Lyle M. Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine. United States. doi:10.1016/j.combustflame.2016.03.031.
O'Connor, Jacqueline, Musculus, Mark P. B., and Pickett, Lyle M. Mon . "Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine". United States. doi:10.1016/j.combustflame.2016.03.031. https://www.osti.gov/servlets/purl/1326655.
@article{osti_1326655,
title = {Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine},
author = {O'Connor, Jacqueline and Musculus, Mark P. B. and Pickett, Lyle M.},
abstractNote = {This work explores the mechanisms by which a post injection can reduce unburned hydrocarbon (UHC) emissions in heavy-duty diesel engines operating at low-temperature combustion conditions. Post injections, small, close-coupled injections of fuel after the main injection, have been shown to reduce UHC in the authors’ previous work. In this work, we analyze optical data from laser-induced fluorescence of both CH2O and OH and use chemical reactor modeling to better understand the mechanism by which post injections reduce UHC emissions. The results indicate that post-injection efficacy, or the extent to which a post injection reduces UHC emissions, is a strong function of the cylinder pressure variation during the post injection. However, the data and analysis indicate that the pressure and temperature rise from the post injection combustion cannot solely explain the UHC reduction measured by both engine-out and optical diagnostics. In conclusion, the fluid-mechanic, thermal, and chemical interaction of the post injection with the main-injection mixture is a key part of UHC reduction; the starting action of the post jet and the subsequent entrainment of surrounding gases are likely both important processes in reducing UHC with a post injection.},
doi = {10.1016/j.combustflame.2016.03.031},
journal = {Combustion and Flame},
number = C,
volume = 170,
place = {United States},
year = {2016},
month = {5}
}

Works referencing / citing this record:

Optical study on characteristics of non-reacting and reacting diesel spray with different strategies of split injection
journal, May 2018

  • Desantes, Jose M.; García-Oliver, José M.; García, Antonio
  • International Journal of Engine Research, Vol. 20, Issue 6
  • DOI: 10.1177/1468087418773012

Optical study on characteristics of non-reacting and reacting diesel spray with different strategies of split injection
journal, May 2018

  • Desantes, Jose M.; García-Oliver, José M.; García, Antonio
  • International Journal of Engine Research, Vol. 20, Issue 6
  • DOI: 10.1177/1468087418773012