Influence of the Post-Injection Pattern on Performance, Soot and NOx Emissions in a HD Diesel Engine 2002-01-0502
The main objective of the study described in this paper is to explore the potential of different post-injection patterns, with a plain common rail system, for reduction of soot emissions in HD diesel engines.
Test have been carried out in a single-cylinder engine at several critical engine operation points from the European Steady state test Cycle (ESC). At these operation points, EGR was introduced to reduce NOx emissions to a given value, and then different post-injection patterns were produced. A parametric study was performed, considering the time between injections and the post-injected fuel mass as the main variables. In every case the total injected fuel mass was kept constant.
Aside from the experimental data obtained in the engine tests, a diagnosis model was applied to calculate heat release laws and other parameters depicting the combustion process.
The results obtained allowed to discern the effects produced by the different post-injection patterns and to assess their potential for Soot emissions reduction, keeping NOx emissions and fuel consumption at the original values.