Investigation on Spray Behavior and NOx Conversion Characteristic of a Secondary Injector for a Lean NOx Trap Catalyst

  • Sangki Park
  • Jungmo Oh
  • Kihyung Lee


Lean NOx trap (LNT) catalyst has been used to reduce NOx emissions from diesel engines. The LNT absorbs NOx in lean condition and discharges N2 by reducing NOx in rich conditions. Thus, it is necessary to make exhaust gas lean or rich conditions for controlling LNT system. For making a rich condition, a secondary injector was adopted to inject a diesel fuel into the exhaust pipe. In the case of secondary injector, the behavior of spray is easily affected by high temperature (i.e., 250 ∼ 350 °C) occurred in the exhaust manifold. Therefore, it is needed to investigate the spray behavior of diesel fuel injected into an exhaust manifold, as well as the conversion characteristics for a lean NOx trap of a diesel engine with LNT catalyst. The characteristics of exhaust emissions in NEDC (New European Driving Cycle) mode were analyzed and spray behaviors were visualized in various exhaust gas conditions. The results show that as the exhaust gas mass flow increases, the spray cone angle becomes broad and the fuel is directed to the flow field. Besides, the cone angle of spray is decreased by centrifugal force caused in exhaust gas flow field. In addition, the effects of nozzle installation degree, injection quantity, and exhaust gas flow on NOx conversion performance were clarified.

Key Words

Diesel engine HC-LNT catalyst After-treatment Spray behavior RMS image Secondary injector 


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Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringHanyang UniversityGyeonggiKorea
  2. 2.Division of Marine EngineeringMokpo National Maritime UniversityJeonnamKorea

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