Experimental investigation of low temperature combustion in a diesel engine depending on injection advance and injection pressure

Abstract

In this study, the performance parameters and emissions of a pre-mixed charge compression ignition were investigated under different injection pressures and injection advances. After the peak engine power was reached, reasonable decreases occurred in brake mean effective pressure at certain injection advances with the increase of injection advance, and dramatic decreases observed when interval was so exceeded. In addition mean indicated pressure and peak in-cylinder pressure were investigated. Considering the emissions, dramatic increases were observed in CO and total hydrocarbon, depending on the increase in the low temperature combustion regime. The NOx started a rapid downward trend after a certain injection advance value in the experimental region, but this effect did not occur at the de?sired level for specific NOx. It was observed that the NO2 to NOx ratio increased as the pre-mixed charge compression ignition became dominant and NO2 production increased among the total NOx. In the operating region where the low temperature combustion regime was dominant, the targeted reduction in NOx and particulate matter emissions was observed, but the desired reduction in specific emissions did not occur. In the low temperature combustion region, the combustion process was prolonged, initially reasonable changes occurred at performance parameters, but unacceptable results were observed at high injection pressures with excessive injection advances.