Influence of Engine Size and Fuel Properties on Exhaust Emissions from Diesel Engines

Nowadays not only small, high speed diesel engines for automobiles, but also larger sized, medium and low speed engines for locomotives, generators and ships will be under some exhaust emissions restrictions. However, not much emissions research work on larger engines has been performed to establish whether measures used for reducing emissions of smaller engines are also effective on larger ones.This present paper covers emission data from four diesel engines having a bore of 110, 200, 320 and 450mm. The influence of (1) the size or speed of engine, (2) the fuel (gas oil or bunker fuel oil) and (3) means used to reduce NOx emissions such as “fuel injection timing retard ”and“exhaust gas re-circulation” are discussed.One reason for higher particulate emissions from bunker fuel oil is clarified using the visualization of burning spray in a model combustion chamber.