Experimental Studies on Dual Fuel Homogeneous Charge Diesel Combustion Engines to Improve Emission Characteristics

The main objective of this work is to study the compatibility of using dual fuels (mixture of gasoline-diesel (G-D) and gasoline-sarasol (G-S)) in Homogeneous Charge Diesel Combustion (HCDC) engine to improve the performance and emission characteristics. The present investigation was carried out in a single cylinder four stroke air-cooled diesel engine of rated power 4.4 kW. The test fuels used were gasoline as premixed fuel, diesel and sarasol (175/360) as main fuel or DI fuel. 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.