Influence of EGR and Pilot Injection on PCCI Combustion in a Single-Cylinder Diesel Engine Korea Advanced Institute of Science and Technology (KAIST)

Format:

Conference/Event

Author/Creator:

Park, Park, author.

Contributor:

Bae, Choongsik

Conference Name:

SAE International Powertrains, Fuels and Lubricants Meeting (2011-08-30 : Kyoto, Japan)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

The effect of pilot injection and exhaust gas recirculation(EGR) on premixed charge compression ignition (PCCI) combustion wasinvestigated in a single-cylinder direct-injection diesel enginewith low engine speed and low load. The injection timing of PCCIcombustion was fixed at 25 ~ 30 crank angle degree before top deadcenter (°CA BTDC) based on the ignition delay and power output. Thelevel of oxides of nitrogen (NOx) emissions of PCCI combustion was68% lower than that of conventional diesel combustion owing to thereduction of near-stoichiometric region which is well known as themain source of NOx formation. However, the indicated mean effectivepressure (IMEP), hydrocarbon (HC), particulate matter (PM) andcarbon monoxide (CO) emissions deteriorated compared withconventional diesel combustion because of early injection, advancedcombustion phase and lowered combustion temperature.EGR has been applied to PCCI combustion. As EGR rate increased,IMEP was increased due to the decrease of negative work during thecompression stroke and NOx emissions was decreased because ofdilution and thermal effects of EGR.The pilot injection with a variation of split ratio and dwelltime was also explored to enhance the mixing of fuel and fresh air.Certain conditions of pilot injection were effective for increaseof IMEP and decrease of CO, HC and PM emissions because in-cylindertemperature was raised due to pilot injection, and this temperaturerise enhanced the evaporation of the main injected fuel. The levelof NOx emissions was higher than that of single injection becauseof raised in-cylinder temperature.Consequently, the power output and emissions could be improvedby applying pilot injection and EGR simultaneously in PCCIcombustion

Notes:

Vendor supplied data

Publisher Number:

2011-01-1823

Access Restriction:

Restricted for use by site license