Influence of Multiple Injection Strategies on Emissions, Combustion Noise and BSFC of a DI Common Rail Diesel Engine

Abstract

<div class="htmlview paragraph">High pressure common-rail injection systems nowadays allow a very high degree of flexibility in the timing and quantity control of multiple injections, which can be used to obtain significant reductions in engine noise and emissions.</div> <div class="htmlview paragraph">The aim of this study is to develop a better understanding of the relationship between injection strategies and the combustion and emission formation process.</div> <div class="htmlview paragraph">Some multiple injection strategies (pilot-pilot-main and pilot-main-after) have therefore been analyzed to highlight their influence on soot, NOx, combustion noise and bsfc (brake specific fuel consumption) on a passenger car DI Diesel engine prototype.</div> <div class="htmlview paragraph">One operating point (2000×2 rpm/bar) was analyzed for the pilot-pilot-main injection strategy while two operating points (1500×5 and 2500×8 rpm/bar) were tested for the pilot-main-after injection strategy.</div> <div class="htmlview paragraph">Finally the main combustion characteristics were determined, for each operating condition, on the basis of the heat release and a correlation was attempted between the combustion parameters and emissions, noise and bsfc.</div>