• Title/Summary/Keyword: Lean NOx Trap

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A Research on the Emissions According to Test Modes of Diesel Vehicles for Euro-6 (Euro-6 대응 경유 차량의 규제 시험모드에 따른 배출가스 성능 비교 분석)

  • Kang, Minkyung;Kwon, Seokjoo;Seo, Youngho
    • Journal of Institute of Convergence Technology
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    • v.8 no.1
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    • pp.5-8
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    • 2018
  • Emissions of diesel vehicles have been regulated by NEDC mode for a long time. However, the NEDC mode has been known the control of emission reduction is not reflected properly on actual road conditions. For these reasons, diesel vehicle emissions are regulated in both NEDC mode and WLTC mode from 2017 to 2020, from 2020 onwards, the emissions of diesel vehicles will measure in WLTC mode only and will not be able to exceed 1.5 times the regulated value. The purpose of this study is to analyze the development trend of diesel vehicle after-treatment system in order to comply with the future regulations on diesel vehicle. As a result, it is essential to reduce the NOx emissions of diesel vehicles for Euro 6, the NOx emissions of the test vehicle equipped with SCR were 30% to 50% loss than the test vehicle equipped with LNT despite the higher curb weight and engine displacement.

Corrosion Characteristics Improvement of Aluminium Tube for Diesel Engine Intercooler with LP-EGR(Low Pressure-Exhaust Gas Recirculation) (LP-EGR이 적용된 디젤 엔진 인터쿨러용 알루미늄 튜브의 내식성 향상)

  • Ahn, Joon;Ha, Seok;Kwak, Dong-Ho;Jung, Byung-Jun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.6
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    • pp.140-145
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    • 2012
  • Recently, various after-treatment systems, such as LP-EGR(Low Pressure-Exhaust Gas Recirculation), SCR(Selective Catalytic Reduction) and LNT(Lean NOx Trap), were developed to obey the stringent emission regulations of diesel engine. There are many researches on LP-EGR system because it has advantages of NOx reduction and low fuel consumption. But, condensation water is generated in internal of intercooler tube and it contains various types of anion that cause the corrosion of aluminium tube. In this study, it is examined that the condensation water effects on corrosion of aluminium tube. And method for improvement of corrosion characteristics is investigated using the dipping and electrochemical test.

The Spray Characteristics and Spray Behavior Characteristic in Exhaust Gas Flow of Urea Solution Injector (Urea 수용액 분사용 인젝터의 분무 특성과 배기관내 분무 거동 특성)

  • Oh, Jung-Mo;Han, Young-Deok;Kim, Ki-Bum;Lee, Ki-Hyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.11
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    • pp.999-1004
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    • 2010
  • Recently, many technologies have been developed in order to satisfy stringent emission regulations. However, in the case of diesel engines, the stringent emission regulations with respect to NOx and PM have not yet been satisfied. A dramatic reduction in the NOx and PM emissions could be achieved by using after-treatment systems such as lean NOx trap (LNT) and urea-SCR systems. However, the high temperature in the exhaust pipe affects the spray behavior of the secondary injector, which is used for supplying the Urea-SCR. Because of this high temperature, it is difficult to achieve uniform distribution of the reducing agent in the manifold. In this paper, the characteristics of a urea-SCR injector used for injecting in the exhaust pipe are presented. The purpose of this study was to investigate the spray characteristics of the injector, such as the spray angle, injection quantity, and SMD. In addition, laser diagnostics and high-speed-camera images were used to analyze the injector spray characteristics and to present a distribution of reduction in the transparent manifold.

Study of the Optimal Calcination Temperature of an Al/Co/Ni Mixed Metal Oxide as a DeNOx Catalyst for LNT

  • Jang, Kil Nam;Han, Kwang Seon;Hong, Ji Sook;You, Young-Woo;Suh, Jeong Kwon;Hwang, Taek Sung
    • Clean Technology
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    • v.21 no.3
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    • pp.184-190
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    • 2015
  • Most of LNT catalysts use noble metals such as Pt for low temperature NOx oxidation but there is an economic weakness. For the purpose of overcoming this, this study is to develop DeNOx catalyst for LNT excluding PGM (platinum group metal) such as Pt, Pd, Rh, etc. To do so, Al/Co/Ni catalyst selected as a preliminary test is used to study fundamental property and NOx’s conversion according to calcined temperature. Ultimately, that is, Al/Co/Ni mixed metal oxide which does not use PGM is selected and physicochemical characterization is performed by way of XRD, EDS, SEM, BET and ramp test and NOx conversion is also analyzed. This study shows that all samples consist of mixed oxides of spinel structure of Co2AlO4 and NiAl2O4 and have enough pore volume and size for redox. But as a result of NH3-TPD test, it is desired that calcined temperature needs to be maintained at 700 ℃ or lower. Also only samples which are processed under 500 ℃ satisfied NO and NOx conversion simultaneously through ramp test. Based on this study’s results, optimum calcined temperature for Al/Co/Ni=1.0/2.5/0.3 mixed metal oxide catalyst is 500 ℃.

A Study on the Characteristic and Droplet Uniformity of Spray Injection to Exhaust Gas Flow from Urea Solution Injector (Urea 수용액의 배기가스 유동장내 분무 특성과 분무 균일도에 관한 연구)

  • Oh, Jung-Mo;Cha, Won-Sim;Kim, Ki-Bum;Lee, Jin-Ha;Lee, Ki-Hyung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.3
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    • pp.83-89
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    • 2011
  • Diesel engines can produce higher fuel efficiency and lower $CO_2$ emission, they are subject to ever more stringent emission regulation. However, there are two major emission concerns fo diesel engines like such as particulate matter (PM) and nitrogen oxides (NOx). Moreover, it is not easy to satisfy the regulations on the emission of NOx and PM, which are getting more strengthened. One of the solutions is to apply the new combustion concept using multistage injection such as HCCI and PCCI. The other solution is to apply after-treatment systems. For example, lean NOx trap catalyst, Urea-SCR and others have various advantages and disadvantages Especially, Urea-SCR system have advantages such as a high conversion efficiency and a wide operation conditions. Hence the key factor to implementation of Urea-SCR technology, good mixing of urea(Ammonia) and gas, reducing Ammonia slip. Urea mixer components are required to facilitate evaporation and mixing because the liquid state of urea poses significant barriers for evaporation, and the distance to mixer is the most critical that affect mixer performance. In this study, to find out the distance from injector to mixer and simulation factor, a laser diagnostics and high speed camera are used to analyze urea injector spray characteristics and to present a distribution of urea solution in transparent manifold In addition, Droplet Uniformity Index is calculated from the acquired images by using image processing method to clarify the distribution of spray.