Investigation of H2 enrichment of ternary blended fuel modified with graphene nanoplate on cycle-by-cycle variations

Abstract

Despite the global goal of achieving e-mobility in the future, the majority of the transportation sector still heavily relies on fossil fuels. Previous studies in the area have revealed the benefits of hydrogen additives and nanoparticles mixed with blended diesel fuels on engine performance and emissions. However, there is a significant gap in the research when it comes to exploring the combination of non-metallic nanoparticle additives with alcohol and diesel blend fuels under dual-fuel mode with hydrogen. In the study, a fuel blend (BF) comprising 80% diesel, 10% n-butanol, and 10% ethanol, which represents a potential alternative fuel composition for compression ignition engines, was specifically focused on. To further enhance the fuel properties and combustion characteristics, the addition of 50 ppm graphene nanoplatelets (GNP) was introduced as a non-metallic additive. By examining this novel fuel composition and investigating its impact under both single and dual-fuel mode, the dimension of hydrogen addition in the dual-fuel mode is aimed to explore potential synergistic effects. A diesel engine was used under dual fuel mode, with hydrogen fed at a rate of 0.25 g/min. The prepared fuels were tested at 1800 rpm engine speed by applying five different loads. 50 ppm GNP of modified fuels resulted in an increase of peak pressures by 3.1%, 4.2%, and 5.6% for DGNP, BFGNP, and BFGNP15H respectively, compared to D. At full load, the COVIMEP values were approximately 0.3%, 0.2%, 0.4%, 1.3%, and 1.6% for D, DGNP, BF, BFGNP, and BFGNP15H, respectively. In the term of thermal efficiency, BFGNP15H had a 3.9% lower BTE than BFGNP at 25% load, but BFGNP15H showed a 0.4% increase in BTE at full load compared to BFGNP. For emission analysis, BFGNP15H showed a reduction of 42.31%, 15.1%, and 10% in CO emissions compared to D, BF, and BFGNP, respectively, under full load in dual operating condition. However, the NO emissions of BFGNP15H were 7.2% higher than those of D under the same condition.