Characteristics of Particulate Emissions from Direct-Injection Diesel Engine

Reduction of Particulate emissions from diesel engine is an important theme from the view point of air pollution. Experiments were carried out using a four-stroke single cylinder direct-injection diesel engine. A new method to measure diesel particulates has been developed. Particulates were sampled with a freezing method just behind an exhaust valve and examined through a scanning electron microscope. Shape, structure and the size distributions of particulates obtained with the above method were measured under wide operating conditions. The total mass of particulate emissions was measured using a dilution tunnel sampling system. The heat release processes were analyzed using indicator diagrams and the relation between burning conditions and particulate emissions was discussed, after systematic experiments under constant revolution speed of 2000 rpm for several load and injection timing condition.