Title: Impact of Injection Strategies on Combustion Characteristics, Efficiency and Emissions of Gasoline Compression Ignition Operation in a Heavy-duty Multi-cylinder Engine

Abstract

Gasoline compression ignition using a single gasoline-type fuel for direct/port injection has been shown as a method to achieve low-temperature combustion with low engine-out NO(x)and soot emissions and high indicated thermal efficiency. However, key technical barriers to achieving low-temperature combustion on multi-cylinder engines include the air handling system (limited amount of exhaust gas recirculation) as well as mechanical engine limitations (e.g. peak pressure rise rate). In light of these limitations, high-temperature combustion with reduced amounts of exhaust gas recirculation appears more practical. Furthermore, for high-temperature gasoline compression ignition, an effective aftertreatment system allows high thermal efficiency with low tailpipe-out emissions. In this work, experimental testing was conducted on a 12.4 L multi-cylinder heavy-duty diesel engine operating with high-temperature gasoline compression ignition combustion with port and direct injection. Additionally, engine testing was conducted at an engine speed of 1038 r/min and brake mean effective pressure of 1.4 MPa for three injection strategies, late pilot injection, early pilot injection, and port/direct fuel injection. Furthermore, the impact on engine performance and emissions with respect to varying the combustion phasing were quantified within this study. At the same combustion phasing, early pilot injection and port/direct fuel injection had an earlier start of combustion andmore » higher maximum pressure rise rates than late pilot injection attributable to more premixed fuel from pilot or port injection; however, brake thermal efficiencies were higher with late pilot injection due to reduced heat transfer. Early pilot injection also exhibited the highest cylinder-to-cylinder variations due to differences in injector behavior as well as the spray/wall interactions affecting mixing and evaporation process. Overall, peak brake thermal efficiency of 46.1% and 46% for late pilot injection and port/direct fuel injection was achieved comparable to diesel baseline (45.9%), while early pilot injection showed the lowest brake thermal efficiency (45.3%).« less

Authors:

Wang, Buyu ^[1]; Pamminger, Michael ^[2]; Vojtech, Ryan ^[3]; Wallner, Thomas ^[1]

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+ Show Author Affiliations

1. Argonne National Lab. (ANL), Argonne, IL (United States)
2. Illinois Inst. of Technology, Chicago, IL (United States)
3. Navistar Inc., Melrose Park, IL (United States)

Publication Date:

Tue Sep 25 00:00:00 EDT 2018

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1657479

Grant/Contract Number:  

AC02-06CH11357; EE0007767

Resource Type:

Accepted Manuscript

Journal Name:

International Journal of Engine Research

Additional Journal Information:

Journal Volume: 21; Journal Issue: 8; Journal ID: ISSN 1468-0874

Publisher:

SAGE

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; Gasoline compression ignition; Brake thermal efficiency; Pilot injection, Port fuel injection; Advanced combustion engines