Mode Transition between Low Temperature Combustion and Conventional Combustion with EGR and Injection Modulation in a Diesel Engine Korea Advanced Inst of Science and Tech

Format:

Conference/Event

Author/Creator:

Kim, Kim, author.

Contributor:

Bae, Choongsik

Han, Sangwook

Conference Name:

SAE 2011 World Congress & Exhibition (2011-04-12 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

Mode transition between low temperature combustion andconventional combustion was investigated in a direct injectiondiesel engine. Low temperature diesel combustion was realized bymeans of high exhaust gas recirculation rate (69~73%) and earlyinjection timing (-28~ -16 crank angle degree after top deadcenter) compared with those (20% exhaust gas recirculation rate and-8 crank angle degree after top dead center) of conventionalcombustion. Tests were carried out at different engine speeds andinjection pressures.Exhaust gas recirculation rate was changed transiently bycontrolling each throttle angle for fresh air and exhaust gasrecirculation to implement mode transition. Various durations forthrottle transition were applied to investigate the effect of speedchange of exhaust gas recirculation rate on the characteristics ofmode transition. Indicated mean effective pressure, intakepressure, maximum pressure rise rate and real-time unburnedhydrocarbon emissions in the exhaust manifold were analyzedtransiently.At the early stage (10 - 20 cycles) of mode transition from lowtemperature diesel combustion to conventional combustion,combustion performance became unstable with high fluctuation inindicated mean effective pressure and rapid increase in maximumpressure rise rate. In the case of mode transition fromconventional combustion to low temperature diesel combustion,combustion performance kept stable without substantial change inindicated mean effective pressure and maximum pressure rise rate.indicated mean effective pressure kept constant at the early stage,but decreased gradually to a lower level.Transient injection strategy, which modulated includinginjection timing and injection quantity, cycle to cycle was appliedto reduce fluctuation of indicated mean effective pressure duringmode transition. This process had the result that the range offluctuation in indicated mean effective pressure decreased andmaximum pressure rise rate was considerably reduced

Notes:

Vendor supplied data

Publisher Number:

2011-01-1389

Access Restriction:

Restricted for use by site license