Effects of low pressure exhaust gas recirculation on regulated and unregulated gaseous emissions during NEDC in a light-duty diesel engine

• Published in: Energy (Oxford) Vol. 36; no. 9; pp. 5655 - 5665
• Main Authors: Bermúdez, Vicente, Lujan, José M., Pla, Benjamín, Linares, Waldemar G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2011; Elsevier
• Subjects: Applied sciences; carbon dioxide; Carbon monoxide; catalysts; Combustion; Diesel; Diesel engines; Energy; energy use and consumption; Engines; Exact sciences and technology; Exhaust; formaldehyde; formic acid; gas emissions; hydrocarbons; Hydrocarbons speciation; Low pressure; Low pressure EGR; New European Driving Cycle; nitrous oxide; Nitrous oxide emission; Nitrous oxides; Non-regulated emissions; ozone; pollutants; temperature; troposphere; Low pressure EGR; Hydrocarbons speciation; New European Driving Cycle; Non-regulated emissions; Nitrous oxide emission
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2011.06.061

Regulated and unregulated gaseous emissions with high pressure and low pressure EGR (exhaust gas recirculation) system were tested in a 4-cylinder, light-duty diesel EURO IV engine typically used in European vehicles. Four different engine calibrations with the low pressure EGR system were studied. Regulated emissions of NO
X
, CO, HC and CO
2 were measured for each configuration. Unburned Hydrocarbon Speciation, HCHO (formaldehyde), HCOOH (formic acid) and N
2O (nitrous oxide) were also measured in order to determine the MIR (maximum incremental reactivity) of the gaseous emissions. Pollutants were measured without the DOC (diesel oxidation catalyst) to gather data about raw emissions. When the low pressure EGR system was used, decreases in NO
X
, N
2O and fuel consumption were observed and significant increases HC, CO and unregulated emissions; this is the result of a lower intake manifold temperature, which provides a higher gas density which modifies the combustion process. The potential of tropospheric ozone production was higher in all cases when the low pressure EGR was used.
► Low pressure EGR loop in direct injection diesel engine as solution for emissions. ► Decrease in the fuel consumption and CO
2 emission in the New European Driving Cycle. ► Increase in Carbon Monoxide and Total Hydrocarbons emissions. ► High potential to tropospheric ozone production with low pressure EGR.