Effects of multiple fuel injection schedules and LPG energy share on combustion stability and output characteristics of dual-fuel HCCI engine

Abstract

Homogeneous Charge Compression Ignition (HCCI) engine is a prominent solution to satisfy the stringent NOx emission norms. The current study investigates the influence of fuel injection strategies and LPG energy share on dual fuel powered HCCI engine at 1.8 bar and 3.6 bar BMEP at constant speed (2700 rpm) and injection pressure (50 MPa). Over the study D + LPO used as primary fuel and LPG as secondary fuel. The fuel injection strategies alike single, double, as well multi-pulse modes are studied at injection timings of 90obTDC aimed at single-pulse, 120°& 90°bTDC for double-pulse, 120°, 90°, & 30°bTDC for multi-pulse modes. All single, double, and multi-pulse injection modes at 0% LPG energy share obtains greater combustion rate and advanced combustion phasing. Further increase in LPG energy share, the rate of combustion is lessened and retarded toward TDC, consequently it enhanced the performance and emission characteristics of an HCCI engine. The optimum LPG energy share for single-pulse, double-pulse, and multi-pulse injections modes are 46.80%, 63.25%, and 78.06% respectively for 1.8 bar BMEP. For 3.6 bar BMEP optimum LPG energy shares are found to be 41.79%, 58.55%, and 71.76% for single, double, and multi-pulse injection respectively.