REDUCTION OF NOx IN A DIESEL ENGINE USING SPLIT INJECTION APPROACH

One of the important goals in diesel engine research is the development of means to reduce the emissions of oxides of nitrogen (NOx) and soot particulates, and in this endeavour advanced techniques like split injection/multiple injection, exhaust gas recirculation (EGR) etc. are being developed. The principle of split injection is that when fuel is injected in two pulses it engenders a reduction in the peak combustion chamber temperature which ensures the reduction in NOx emission. In this study to achieve split injection in an economical manner, a double lobed cam has been designed incorporating the optimum split and dwell. Experimental study indicates that 50-50 split with 10 degree crank angle dwell is the optimum to achieve a viable reduction in NOx without any major penalty in soot and power. A 15% reduction in NOx and 10% reduction in soot was observed on incorporating these results.