Experimental effect of CuO2 nanoparticles into the RME and EGR rates on NOX and morphological characteristics of soot nanoparticles

In recent years, the adding nano additives to the fuel is paid much attention by decreasing the exhaust emissions and enhance combustion characteristics without any modifications in diesel engine. The effects of copper dioxide (CuO2) nanoparticles and exhaust gas recirculation (EGR) on combustion characteristics and morphological characteristics of soot nanoparticles in diesel engine fuelled with rapeseed methyl ester (RME) were investigated in this study. The good advantages of CuO2 nanoparticles such as good thermal properties, oxygen storage, and density thermophysical properties of viscosity are encourage to using as nano additives into the biodiesel. The results showed that the pressure inside cylinder and ROHR improved by 4% and 11%, respectively, from adding CuO2 nanoparticles into the RME in comparison neat RME. Furthermore, the BTE increased by 3.64%, 7.36%, 9.28% and 12.43% with adding CuO2 to the RME, while the BSFC decreased by 5.26%, 7.47%, 9.68% and 12.73% when adding nanoparticles to the RME under 25%, 50%, 75% and 100% of engine load, respectively, in comparison with diesel fuel. Adding CuO2 nanoparticles to the RME and 20% rate of EGR significantly decrease the NOX emissions by 29.64% when compared to the without nano additives. The number and concentration of soot nanoparticles were decreased with addition of CuO2 nanoparticles to the RME and they increased with presence EGR technology. It is indicated that the soot nanoparticles concentration decreased or was in par with neat RME when incorporation between EGR and nano additives. The morphological parameters such as number of soot primary particles (npo) exhibits significant reduction by 18%, meanwhile slightly increase in the average diameter of soot primary particles (dpo) by 7% with adding CuO2 to the RME for with and without EGR.