Investigation of the Effects of Diesel Injection Strategies in a Reactivity Controlled Dieseliso-Butanol Compression Ignition Engine

Due to very low PM and NOx emissions and considerable engine efficiency, dual-fuel combustion mode such as RCCI strategy attracted lots of attention compared to other combustion modes. In this numerical research work, the impacts of direct injection timing and pressure of diesel fuel on performance and level of engine-out emissions in a diesel-butanol RCCI engine was investigated. To simulate the combustion process, a reduced chemical kinetic mechanism, which consists of ۳۴۹ reactions ۷۶ species was used. The influence of thirty-six various strategies based on two diesel spraying characteristics such as injection pressure (۶۵۰, ۸۰۰, ۱۰۰۰, and ۱۲۰۰ bar) and diesel spray timing (۳۰۰ to ۳۴۰ CA with ۵ CA steps) have been examined. Results indicated that, under the specific operating conditions like ۱۰۰۰-bar spray pressure by direct injection at ۴۵ CA BTDC and the spray angle of ۱۴۵ degrees, the level of cylinder-out pollutants such as CO (up to ۲۶%), NOx (about ۸۶%), PM (by nearly ۷۱%) and HC (about ۱۷.۲۵%) have been simultaneously reduced. Also, ISFC decreased by about ۲.۳%, IP increased by about ۲.۴%, and also ITE improved by nearly ۲% compared to the baseline engine operating conditions.

Keywords:

RCCI Engine , Diesel-Butanol , Injection Strategies , Emissions , Performance