Improving Environmental Safety of Diesel Engines by Changing Fuel Injection Duration

The aim of the study was to quantify the effect of fuel injection duration on the formation of toxic components in diesel exhaust gases to substantiate measures for reducing technogenic load. Bench tests of the 6ChN 15/18 (D6N-250) diesel engine with a power of 189 kW at 1 900 rpm were carried out according to GOST 31967–2012, GOST 24028–2013 using the 13-mode test cycle. The injection duration was varied from 20 to 35° CA, exhaust gas sampling and analysis were performed, and particulate matter dispersion was determined. It was found that increasing the injection duration from 20 to 35° CA leads to an increase in incomplete combustion products: CO emissions increase by 1,93 times, particulate matter by 1,35 times, hydrocarbons by 1,64 times. Simultaneously, nitrogen oxide emissions decrease by 2,27 times due to the shift of the combustion process to the expansion line. An increase in the average diameter of particulate matter was revealed with extended injection. Comparison with environmental standards showed that none of the studied modes ensures compliance with EURO 4–6 standards for all components; particulate matter emissions exceed EURO 6 standards by 35 times. The scientific novelty lies in obtaining quantitative relationships between injection duration and the formation of toxic components for the 6ChN 15/18 diesel engine. The practical significance consists in substantiating the need for an integrated approach combining optimization of injection duration with the use of particulate filters or catalytic converters.