The Effect of Exhaust Gas Recirculation on Combustion and NOx Emissions in a High-Speed Direct-injection Diesel Engine

Effect of Exhaust Gas Recirculation (EGR) on Performance and Emission of a Compression Ignition Engine with Staged Combustion (Insertion of Unburned Hydrocarbon)

“…hot EGR. An increase in in let charge temperature always results in shorter ignition delay and may imp rove thermal efficiency [34]. If the exhaust gas is cooled before recirculat ion to combustion chamber, then it is called cooled EGR.…”

Membrane-Based Air Composition Control for Light-Duty Diesel Vehicles: A Benefit and Cost Assessment

“…One such technique is exhaust-gas recirculation (EGR), in which part of the exhaust gas is mixed with the ambient intake air. This method, the most costeffective way of reducing NO x emissions from spark-ignition (SI) engines, is being considered by many investigators for use with compression-ignition (CI) engines (Dürnholz et al 1992;Ladommatos et al 1996;Psaras et al 1997). However, its applicability for diesel engines is uncertain because of such drawbacks as increases in both particulates and smoke at higher engine loads, reduced engine durability (Nagai et al 1983), and possible oil contamination caused by sulfur dioxide (SO 2 ) and soot particles in recirculated exhaust gas (Nagaki and Korematsu 1995).…”

Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

“…Hu et al [12] showed the reduction in NOx emission with increase in EGR rate and attributed this effect to the presence of high heat capacity gases such as N2 and CO2 which changed the heat capacity of the combustible mixture reduced the combustion temperature and thus NOx emission. Ladommatos et al [16] explains that the NOx emissions can be reduced by cooling the exhaust gas before it enters the inlet manifold. In case of hot EGR, the temperature is already higher than the intake air; hence heat absorption is not possible to prevent NOx formation.…”

“…Engines that are equipped with EGR have lesser quantity of exhaust at the tail pipe [16]. For a given volumetric concentration, the quantity of harmful elements emitted is lowered; however the quality may remain the same.…”