Cylinder Selective Combustion, the New Diesel Dual Fuel Combustion Control Concept for Low Load Operating Condition

Diesel dual fuel (DDF) operated under moderate load condition emits a lot of CH₄ and CO. Even these emissions have been improved significantly by Dual Fuel Premixed Charge Compression Ignition: DF-PCCI [3] combustion control technique which was proposed by the authors. However, the emission was still high as compared to diesel emissions. To overcome this problem, the new combustion control concept so called Cylinder Selective Combustion (CSC) has been proposed. From the fact that at low load condition, diesel combustion has lower CH₄ and CO emissions than DDF combustion and DDF emissions can be improved significantly by DF-PCCI concept at higher load. So, in the new concept, some cylinder was selected to run with very low IMEP diesel combustion and some cylinder was selected to run with higher IMEP DF-PCCI combustion. The IMEP ratios between DF-PCCI and diesel have been optimized for each engine speed and engine load. The engine and vehicle test results showed that the CSC concept could be utilized with smooth engine running without any misfire meanwhile the CH₄ and CO emissions can be reduced significantly.