Effect of fuel injection pressure on diesel particulate size and number distribution in a CRDI single cylinder research engine

Particulate and NOx emissions from diesel engine are the biggest challenges faced in making diesel engines environmentally benign. Measures adopted for reducing gravimetric particulate emission to meet the prevailing emission regulations necessarily always do not reduce particulate number concentration, which has profound adverse health effects. Therefore it is important to investigate effect of fuel injection parameters, especially fuel injection pressure and start of injection timings on particulate size and number distribution in diesel exhaust. In the present study, a single cylinder research engine is used for experimental assessment of the effects of fuel injection strategies and start of fuel injection timing on particulate size-number, surface area, and volume concentration distributions by using engine exhaust particulate sizer (EEPS) spectrometer. Investigations have been conducted at three different fuel injection pressures (300, 500, 750 bar) and four different start of injection timings. The experimental data indicates that the particulate size-number concentration increases with increasing engine load (BMEP) and it reduces with increasing fuel injection pressure.