Optimization of engine operating conditions and investigation of nano-particle emissions from a non-road engine fuelled with butanol/diesel blends

This study presents the experimental investigation of performance and emission characteristics (including nano-particle emissions) of a non-road diesel engine fuelled with neat diesel and butanol/diesel blends. Experiments were performed at optimal engine operating conditions for a constant engine speed of 1500 rpm. To find the optimal engine operating conditions, first experiments were conducted using diesel fuel. Engine operating parameters were optimized for higher brake thermal efficiency and lower exhaust emissions (i.e. gaseous as well as nano-particle emissions). Taguchi's design of experiment was used to optimize the compression ratio, injection pressure and engine operating load. To investigate the effect of butanol blends on the performance and emissions characteristics, experiments were conducted at three different butanol/diesel blend ratios (i.e. 10, 20 and 30% of butanol by volume) at optimum engine operating conditions. Results indicate that butanol/diesel blends have the potential to reduce CO, NO and particle emissions. The results also revealed that the concentration of ultrafine particle number reduces with diesel/butanol blends for all tested load conditions. The highest reductions in total particle number concentration for all butanol blends were found at 25% and 50% engine load conditions, as compared to neat diesel.