Oxides of Nitrogen and Soot Trade-off Characteristics of Methyl Esters in a Hybrid Mode Compression Ignition Engine

Partially pre-blended compression ignition engine reduces the discharge of oxides of nitrogen and soot. The aim of this research is to study the combustion and emission parameters of hybrid mode compression ignition (HBMCI) at different hybrid ratios. In this system, the percentage of fuel is introduced in the intake manifold is varied according to hybrid ratios. The remaining part of the fuel is injected straight into combustion chamber prior to the end of the compression stroke to trigger the combustion event. The pre-blended charge is burnt in the cylinder along with the fuel directly injected into the cylinder by a conventional injection system. The brake thermal efficiency at rated power output in Hybrid Mode Diesel-JOME (HBMDJ Mode) is observed from 26.8% to 21.6% and in Hybrid Mode Diesel-FOME (HBMDF Mode) is observed from 26.4% to 21.4%, when the hybrid ratio changed from 0.25 to 0.75, compared to 28.4% in diesel mode. The hybrid ratio of 0.25 is observed to be optimum in both HBMDJ and HBMDF. At this hybrid ratio, decrease in brake thermal efficiency is marginal compared to diesel mode. Significant reduction in soot emission is also found than that of diesel mode. From the above investigation, it can be seen than HBMDJ mode was better than HBMDF mode by comparing the performance, combustion and emission characteristics.