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

Article

Abstract

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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References

  1. Alimin, A., Benjamin, S. and Roberts, C. (2009). Lean NOx trap study on a light-duty diesel engine using fast-response emission. Int. J. Engine Research 10,3, 149–164.CrossRefGoogle Scholar
  2. Arcoumanis, C., Hadjiapostolou, A. and Whitelaw, J. (1991). Flow and combustion in a hydra direct-injection diesel engine. SAE Paper No. 910177.Google Scholar
  3. Chaves, H. and Hentschel, W. (1996). In cylinder high speed and stroboscopic video observation of spray development in a DI diesel engine. SAE Paper No. 961206.Google Scholar
  4. Cronhjort, A. and Wahlin, F. (2004). Segmentation algorithm for diesel spray image analysis. Applied Optics 43, 32, 5971–5980.CrossRefGoogle Scholar
  5. Han, M. and Lee, B. (2015). Control oriented model of a lean NOx trap for the catalyst regeneration in a 2.2 L direct injection diesel engine. Int. J. Automotive Technology 16, 3, 371–378.CrossRefGoogle Scholar
  6. Heywood, J. B. (1988). Internal Combustion Engine Fundamentals. McGraw-Hill. New York, USA.Google Scholar
  7. Hiroyasu, H. and Arai, M. (1990). Structures of fuel sprays in diesel engines. SAE Paper No. 900475.Google Scholar
  8. Jeong, H. and Lee, K. (2006). Investigation of the relationship between liquid characteristics and spray mean diameter. 19th Annual Conf. Liquid Atomization and Spray System.Google Scholar
  9. Kang, J., Bae, C. and Lee, K. (2003). Initial development of nonevaporating diesel sprays in common-rail injection systems. Int. J. Engine Research 4, 4, 283–298.CrossRefGoogle Scholar
  10. Ko, S., Oh, K., Seo, C. and Lee, C. (2014). Charateristics on NOx adsorption and intermediates of LNT catalyst. Int. J. Automotive Technology 15, 3, 347–352.CrossRefGoogle Scholar
  11. Lee, B., Song, J., Chang, Y. and Jeon, C. (2010). Effect of the number of fuel injector holes on characteristics of combustion and emissions in a diesel engine. Int. J. Automotive Technology 11, 6, 783–791.CrossRefGoogle Scholar
  12. Lee, K. and Reitz, R. (2004). Investigation of spray characteristics from a low-pressure common rail injector for use in a homogeneous charge compression ignition engine. Measurement Science Technology 15, 3, 509–519.CrossRefGoogle Scholar
  13. Nam, G., Park, J., Lee, J. and Yeo, G. (2007). The effect of an external fuel injection on the control of LNT system the diesel NOx reduction system. SAE Paper No. 2007-01-1242.Google Scholar
  14. Oh, J., Lee, K. and Jeong, H. (2008a). Study on the spray behavior and diesel fuel distribution characteristics of a secondary injector for a lean NOx trap catalyst. Energy & Fuels 22, 3, 1527–1534.CrossRefGoogle Scholar
  15. Oh, J., Lee, K. and Lee, J. (2008b). A study on the optimal injection conditions for an HC-LNT catalyst system with a 12-hole type injector. J. Thermal Science and Technology 3, 2, 278–291.MathSciNetCrossRefGoogle Scholar
  16. Oh, J. and Lee, K. (2014). Spray characteristics of a urea solution injector and optimal mixer location to improve droplet uniformity and NOx conversion efficiency for selective catalytic reduction. Fuel, 119, 90–97.CrossRefGoogle Scholar
  17. Park, J., Lee, S., Lee, H., Park, J., Lee, J. and Kim, H. (2010). Development of control logic and optimization of catalyst in DeNOx system with secondary injection for Euro 6. SAE Paper No. 2010-01-1067.Google Scholar
  18. Shao, J., Yan, Y., Greeves, G. and Smith, S. (2003). Quantitive characterization of diesel sprays using digital imaging techniques. Measurement Science Technology 14, 7, 1110–1116.CrossRefGoogle Scholar
  19. Shoji, A., Kamamoshita, S., Watanabe, T. and Tanaka, T. (2004). Development of a simultaneous reduction system of NOx and particulate matter for light-duty truck. SAE Paper No. 2004-01-0579.Google Scholar

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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