• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.163-166
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• 2009

현재 자동차 검사 또는 정비 현장에서는 특정 삼원촉매변환기가 요구 내구 수명을 제대로 만족시키지 못하여 파손되는 사례가 발생되고 있다. 이러한 삼원촉매장치의 경우 배기가스 변환 효율이나 압력강하 등은 엔진 효율 측면에서 만족되지만 열적 내구성은 만족되지 못한다. 본 연구에서는 열유동 해석 및 구조 해석을 통하여 국내 승용차용 삼원촉매 변환기의 대한 열적 안전성에 대하여 검토하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.13-19
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• 2013

This study examines thermal safety on three-way catalyst that dominates 70% among whole exhaust gas purification device in 2003. Three-way catalyst maintains high temperature in interior domain but maintains low temperature on outside surface. Therefore this device shows tensile stress on outside surface. Temperature distribution of three-way catalyst was acquired by thermal flow analysis for predicted thermal flow parameter. Thermal stress analysis for three-way catalysis was performed based on this temperature distribution. Thermal safety of three-way catalyst was estimated by strength reduction factor and failure probability.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.101-108
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• 2011

On cold start operation of an SI engine, a catalyst shows poor performance before it reaches activation temperature. Therefore, fast warmup of the catalyst is very crucial to reduce harmful emissions. In this study, an appropriate control strategy is investigated to increase exhaust gas temperature through changes of spark timing. Combustion stability is also considered at the same time. Exhaust gas temperature and pressure of combustion chamber are measured to investigate the effects of spark timings on cold start and idle performance. Experiments showed that retarded spark timing promotes the combustion at the end of expansion stroke and increases exhaust gas temperature during cold start.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.167-168
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• 2003

우리나라는 1987년 7월부터 휘발유 및 LPG 연료 사용 자동차에 배출가스 저감장치인 삼원촉매(3way catalytic converter)를 부착하였고 배출가스 측정방법도 중량규제(ｇ/km)로 하였다. 그러나 이륜자동차는 2001년부터 2행정기관에 대해서 산화촉매를 부착토록 하였으며, 오염물질 측정방법도 2000년에 이르러 정지가동시 측정하는 농도규제(%)에서 트랜지언트(transient)방법에 의한 중량규제(ｇ/km)로 강화하였다. (중략)

• Analytical Science and Technology
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• v.18 no.3
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• pp.241-249
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• 2005

In this study, instrumental neutron activation analysis was used to measure the concentrations of about 30 trace elements in airborne particulate (PM2.5) samples at urban area of Daejeon city located in the southwestern region of Korea. An inspection of the measurement data indicates that the distribution patterns of trace elements could clearly distinguish the elements with their concentrations ranging over five orders of magnitude. The mean values for Lu and Dy were found to be the lowest at values of 0.01 and $0.04ng/m^3$, while those for K and Fe showed the highest value of 671 and $653ng/m^3$, respectively. The results of correlation analysis showed that PM2.5 concentrations can exhibit much more enhanced correlations with the elements of earth crustal components. The results of factor analysis further indicated that there are no more than six factors with statistical significance, which may exert dominant roles in regulating the elemental concentration levels in the study area. Enrichment factor analysis supports explicit interpretation of results found by this factor analysis.

• Fire Science and Engineering
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• v.30 no.3
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• pp.1-6
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• 2016

More than five thousands transportation fires occurannually in Korea and the resulting destruction of property and loss of life is huge and results in traffic and environmental pollution. The recent development of automobile technology such as the hybrid concept and use of bio fuels makes fire protection even more difficult due to a lack of understanding of the new adapted system including vehicle engines. In this study, a numerical simulation was performed on a PSR (perfectly Stirred Reactor) to simulate an automobile engine and to clarify the effect of gasoline/ethanol surrogates as a fuel. The temperature, NOx and soot emissions were predicted to decrease with increasing ethanol content, but that of unburned hydrocarbons was found to increase dramatically. The result will provide not only the basic thermal characteristics for engines and their after-treatment systems, but also make it possible to assess the potential for fire events in these systems when an ethanol mixed fuel is used in gasoline vehicles.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.99-110
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• 1999

With a growing awareness, transportation is the maior source of urban air pollution. Planners and policy-makers are strongly urged to care the impacts of transportation management strategies on environment. Since transport-related air Pollution can be regarded as negative externalities of transport, it is indispensable to evaluate chanties in air quality which seems to occur when proposed transport measures are implemented. In addition, transport measures should be integrated in a set of combined Paradigm regarding transport and environment. Based on the integrated Paradigm between transportation demand management(TDM) and environmental planning, the main focus is given to apply environment cost internalizing measures to the short-term congestion management Program(SCMP) in Seoul, that has been developed in 1998 by Seoul Development Institute. Three modules are analyzed: without and/or with ￦500, ￦1000 emission plus gas tax, respectively. From the empirical applications on Seoul city, one of the most exemplary findings in SCMP program is that, emission plus gas tax can be a very useful measure to reduce vehicular emissions by targeting major Pollutants differently, rather than by dealing with pollutants collectively. Further research that provides (1)showing the spatial variation of pollution levels along the intersections, (2)more developing combined Paradigm between transport, land use, and environment, (3)using environmental road capacity rather than Physical-aspects of road capacity, and (4)continuing R&D on air quality constrained TDM, can contribute significantly to applications of the real and efficient environment-constrained transportation planning.