Effect of Dual Fuel Homogenous Charge Diesel Combustion for Simultaneous Reduction of NOx and Smoke-an Experimental Study

The present work focuses on reducing oxides of nitrogen (NOx) and smoke emissions significantly and simultaneously without much compromise in efficiency by involving simple and cost-effective in-cylinder modifications i.e., Homogeneous Charge Diesel Combustion (HCDC) using dual fuels (mixture of gasoline- diesel (G-D) and gasolinesarasol (G-S)). The experiments have been carried out on a single-cylinder, four-stroke, direct injection diesel engine developing 4.4 kW at 1500 rpm. The study had been carried out by fabricating a diesel engine into HCDC mode to install a port fuel injector at intake manifold to create a homogenous charge. The injection timing and duration of the premixed charge was electronically controlled for which electronic fuel injection controller was developed. Gasoline was premixed and port injected before ignition whereas the diesel/sarasol was injected by the conventional injector directly into the cylinder and tested for various premixed percentages, however 10% and 40% was optimized in case of lower and upper limits. It was found that the effect of reduction in NOx and smoke with sarasol in HCDC mode is appreciable than diesel as secondary fuel. With G-S NOx and smoke was reduced by 56.15% and 2.1 BSU respectively whereas with G-D NOx and smoke was reduced by 51.09% and 1.9 BSU respectively. This significant reduction in emissions is due to the thermodynamic physical and chemical properties of sarasol 175/360 apart from HCDC contribution.