Large-scale diesel engine emission control parameters☆

Abstract

Abstract Emission tests were carried out on a large-scale medium-speed supercharged diesel engine (∼1 MW per cylinder) with control parameters compression ratio, start of ignition (SOI) and fuel type (light and heavy fuel oil, LFO and HFO). Emissions of NO x , CO, hydrocarbons (HC), smoke (FSN) and particulate matter (PM) were measured and are discussed in relation to the control parameters. Regarding turbocharger influence on emissions the control parameters by-pass and waste-gate are also briefly addressed. The results show that NO x , CO and FSN decrease while HC emissions increase with later SOI (more delay) for all loads (25–100%). The influence of compression ratio (CR) on NO x is the inverse of this; decreasing CR gives increased NO x . Nozzle design is important for emissions control and less holes and bigger diameter for a certain injection angle seems preferable. Fuel type is important too, and in general LFO produces less gaseous or particulate emissions. Diesel engine turbocharger by-pass and waste-gate valves do affect the emissions. PM emissions were found to decrease with the load (∼Bmep) for propulsion mode, showing an increase with load for generator mode for HFO; for LFO decreasing PM emissions were found with increasing load for both generator and propulsion mode.