Impact of engine combustion on the reactivity of diesel soot from commercial vehicle engines

Abstract

The regeneration behavior of diesel particulate filters is significantly influenced by the reactivity of the stored soot. However, there is still a lack of analyses which describe the effects that various engine operating parameters have on soot reactivity. A medium-duty OM936 single-cylinder engine with a common rail injection system was used to analyze the correlations between engine speed, swirl, combustion air–fuel ratio and soot reactivity. Diesel particulate samples were directly collected from the exhaust stream. The temperature programed oxidation was used to reveal the reactivity to oxygen of the soot samples. Diesel particulate filter regeneration experiments were additionally carried out on a medium-duty OM936 full engine test bench to analyze the influence of soot reactivity on the regeneration efficiency in particulate filters. The results give new insights into the relation between the diesel engine combustion process and soot reactivity and show how the active regeneration of diesel particulate filters is affected by soot reactivity.