EXPERIMENTAL INVESTIGATION ON THE CHARACTERISTICS OF DIESEL FUEL IN A DI DIESEL ENGINE USING TWO STAGE CAMS SPLIT INJECTION METHOD

One of the important roles in diesel engine research is the development of a means to reduce the emission of oxides of Nitrogen (NOx). An experimental investigation has been carried out to investigate the performance and emission characteristics particularly to reduce the NOx emission using split injection method involving double lobed cam in a direct injection single cylinder diesel engine. A different type of double lobed cam (two stage cam) has been designed to inject the diesel fuel in the proportions- 40%-60% and 30%-70% with interval of 6˚ and 8˚ crank angle (CA) between two injections. The engine was tested at a constant speed of 1500 rpm using eddy current dynamometer from no load to full load with the standard injection timing of 27˚ before top dead center (BTDC). The performance parameter such as brake thermal efficiency, the emission parameter such as NOx and smoke values were evaluated using diesel fuel for both single and split injection and compared. The combustion characteristics such as pressure and heat release rate also evaluated and compared. The result shows that the NOx emission was drastically reduced to about 48% for the split injection proportion of 30%-70% with interval of 8˚ CA between two injections while causing a minor decrease in engine efficiency.