Improving Diesel Engine Performance Using Low and High Pressure Split Injections for Single Heat Release and Two-Stage Combustion Univ. of Wisconsin Madison

Format:

Conference/Event

Author/Creator:

Swor, Swor, author.

Contributor:

Andrie, Michael

Kokjohn, Sage

Reitz, Rolf D.

Conference Name:

SAE 2010 World Congress & Exhibition (2010-04-13 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

This study explores an Adaptive Injection Strategy (AIS) thatemploys multiple injections at both low and high pressures toreduce spray-wall impingement, control combustion phasing, andlimit pressure rise rates in a Premixed Compression Ignition (PCI)engine. Previous computational studies have shown that reducing theinjection pressure of early injections can prevent spray-wallimpingement caused by long liquid penetration lengths. Thisresearch focuses on understanding the performance and emissionsbenefits of low and high pressure split injections throughexperimental parametric sweeps of a 0.48 L single-cylinder testengine operating at 2000 rev/min and 5.5 bar nominal IMEP. Thisstudy examines the effects of 2nd injection pressure, EGR, swirlratio, and 1st and 2nd injection timing, for both single heatrelease and two-peak high temperature heat release cases.In order to investigate the AIS concept experimentally, aVariable Injection Pressure (VIP) system was developed. The VIPsystem is capable of both low and high pressure injections (~300bar and ~1200 bar respectively) through one injector in the samecycle. For both the single heat release and TSC experiments,optimal operating conditions were found. The single heat releasecases tended to have better fuel economy and lower emissions thanthe TSC cases. However, the peak pressure rise rates (PRR) for thesingle heat release cases were typically above 6 bar/deg whereasTSC peak PRR were typically under 3 bar/deg. Further, for thesingle heat release cases, it was found that high EGR ratessufficiently suppressed the first stage of combustion allowing thecombustion phasing to be controlled by the second injection. TheTSC combustion phasing of both heat releases could be controlledwith injection timing and EGR. Emission and engine performancetrade-offs were observed over the injection timing ranges for allcases. Variable pressure injection was also compared to a highlydilute (~67% EGR) low temperature combustion (LTC) and was found toproduce slightly higher emissions while maintaining the same engineperformance at a lower EGR rate (~55%)

Notes:

Vendor supplied data

Publisher Number:

2010-01-0340

Access Restriction:

Restricted for use by site license