• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.92-99
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• 2011

To measure the traffic pollutants with high temporal and spatial resolution under real conditions, a mobile emission laboratory (MEL) was designed. The equipment of the mini-van provides gas phase measurements of CO, NOx, $CO_2$, THC (Total hydrocarbon) and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and a condensation particle counter (CPC). The inlet sampling port above the bumper enables the chasing of different type of vehicles. This paper introduces the technical details of the MEL and presents data from the car chasing experiment of diesel bus equipped with aftertreatment system. The dilution ratio was calculated by the ratio of ambient NOx and tail-pipe NOx. Most particles from the diesel bus were counted under 300 nm and the peak concentration of the particles was located between 30 and 60 nm. The total PM number emission from diesel bus equipped with DPF was 10 orders of magnitude lower compared to those emitted from base diesel bus. And the total PM number emission from diesel bus equipped with SCR was comparable to the particle emission from base diesel bus.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.43-49
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• 2009

A catalyzed diesel particulate filter (CDPF) causes the progressive increase in back pressure of an exhaust system due to the loading of soot particles. To minimize pressure drop which is generated by CDPF, the filter should be regenerated when it collects a certain quantity of soot. It is important to know characteristics of regeneration of CDPF with various of exhaust gas temperatures and compositions. The oxidation of HC in DOC leads to increase gas temperature of DOC downstream. The increased gas temperature by DOC has an positive effect on CDPF regeneration. This study presents characteristics of regeneration of CDPF with DOC according to various gas composition, such as HC and $O_2$ concentration. The test-rig is used to control each gas composition and temperature during regeneration of CDPF. Experimental results indicate that the increased concentration of $O_2$ regenerates DPF more actively. With increasing HC concentration, the gas temperature of CDPF upstream increased due to more oxidation of HC. But excessive supply of HC leads to decrease of $O_2$ concentration in the CDPF, which makes it hard to regenerate CDPF.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.1-11
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• 2006

Non-thermal plasma technology for air pollution control, which are NOx, SOx, VOCs, soot, etc., is reviewed. In the early parts of the paper, generation of non-thermal plasma and plasma chemical process are introduced to provide an appropriate plasma condition (electron energy density) for treating air pollutions. Recent results on numerical simulation, optical diagnostics, and gas treatment are provided to characterize an optimal design of plasma generation and plasma chemical process. These data are also helpful to understand unique features of non-thermal plasma process that is achieved with relatively low temperature conditions, i.e. low enthalpy conditions of the treated gas molecules. In the later parts of the paper, several examples of recently developed non-thermal plasma techniques are illustrated, in which technical and economical assessments of the present techniques are provided.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.2 s.257
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• pp.188-194
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• 2007

New diesel engines equipped with common-rail injection systems and advanced engine management control allow drastic decreases in the production of particulate matters and nitrogen oxides with a significant advantage in terms of the fuel consumption and $CO_2$ emissions. Nevertheless, the contribution of exhaust gas after treatment in the ultra low emission vehicles conception has become unavoidable today. Recently the passive type DPF(Diesel Particulate Filter Trap) system for diesel passenger vehicle has been manufactured into mass production from a French automotive maker since the year of 2000. This passive DPF system fully relies on the catalytic effects from additives blended into the diesel fuel and additives injected into the DPF system. In this study, the effects of PM regeneration in the commercial diesel passenger vehicle with the passive type DPF system were investigated in chassis dynamometer CVS(constant volume sampler)-75 mode. As shown in this experimental results, the DPF regeneration was observed at temperature as low as $350^{\circ}C$. And the engine-controlled the DPF regeneration founded to be one of the most promising regeneration technologies. Moreover, the durability of this DPF system was evaluated with a season weather in terms of the differential pressure and exhaust gas temperature traces from a road test during the total mileage of 80,000km.

• Journal of ILASS-Korea
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• v.29 no.2
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• pp.68-74
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• 2024

As awareness of environmental pollution problems increases worldwide, interest in air pollutants is increasing. In particular, NOx and PM, which are major pollutants in diesel vehicles, are contributing significantly to emissions. As a result, its importance is increasing. In this study, based on research results applied to large diesel vehicles, the problem of natural regeneration caused by low exhaust gas temperature during low speed and low load operation is solved by applying a complex regeneration DPF that is not affected by temperature conditions to small diesel vehicles. The feasibility of application to small diesel vehicles was reviewed by measuring the emission reduction efficiency. As a result of the engine test, the power reduction rate and fuel consumption rate before and after device installation under full load conditions were 2.9% decrease and 3.5% increase, respectively, satisfying the standard for a 5% reduction, and as a result of the regeneration equilibrium temperature (BPT) test, the regeneration temperature was 310℃. appeared at the level. The reduction efficiency test results for the actual vehicle durability test equipment showed 97.3% PM, 51.0% CO, and 31.1% HC, while the city commuter vehicle had PM 97.5%, CO 61.7%, HC 40.0%, and the school bus vehicle had PM 96.8%, CO 44.4%, HC 34.3%, and low-speed logistics vehicles showed a reduction efficiency of 98.2% for PM, 36.0% for CO, and 45.7% for HC. Based on the results of this study, in the future, it is necessary to secure DPF technology suitable for all vehicle types through actual vehicle application research on temperature condition-insensitive composite regenerative DPF for medium-sized vehicles.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.525-531
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• 2011

Exhaust gas recirculation (EGR) is more effective than selective catalytic reduction (SCR) or lean $NO_x$ trap (LNT) for the reduction of $NO_x$ emissions in diesel engines. A large amount of EGR gas is necessary to satisfy the stringent regulations on $NO_x$ emissions. Low pressure loop (LPL) EGR is almost independent of the variable geometry turbocharger (VGT) at a specific boost pressure, so LPL EGR is better than conventional high pressure loop (HPL) EGR in terms of EGR supply. We compare the influence of HPL EGR and LPL EGR on the combustion characteristics at a constant boost pressure in a diesel engine. The dilution ratio was employed as an independent parameter to analyze the effect of the dilution of the intake charge for each EGR loop. At the same level of $NO_x$ emissions, the fuel consumption and smoke opacity were slightly lower for LPL EGR than for HPL EGR.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.3
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• pp.8-15
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• 1983

1960년초 이래 우리나라는 고도의 경제성장을 이룩하게 되었으며 이러한 경제성장에 따른 산업화 사회의 특징인 공업화 도시화 인구집중 현상은 우리나라에도 심각한 환경오염 문제를 야기시켜 왔다. 또한 같은 기간동안 자동차의 보유대수 역시 급격한 증가를 보여왔던바, 1962년 30,000 대에서 1982년도 자동차 등록대수는 약 640,000대로 증가하게 되었으며 대부분의 자동차가 대 도시에 집중되어 있다. 특히 전체 차량의 40%가 집중되어 있는 서울시의 경우에는 자동차 배 출가스로 인한 대기오염문제가 도시민의 건강과 재산에 많은 피해를 일으키게 되었다. 우리나 라는 선진 외국의 대도시에 비해 자동차의 1일 주행거리가 3배 내지 5배를 더 주행하고 있고 자동차 배출가스 기준의 완화, 노후차량의 증가, 도로율의 불황 및 도로조건의 불비 등은 도시 중심천의 자동차 집중현상과 함께 자동차 배출가스로 인한 대기오염 문제가 보다 더 심각하게 우려되었고, 따라서 자동차 배출가스규제 강화의 필연성이 계속해서 주장되어 왔다. 자동차로 인한 공해문제는 1940년도 후반 미국 남부 California 지방에서 광화학스모그의 발생과 함께 거 론되기 시작하였으나 본격적으로 문제가 제기된 것은 급격한 자동차 증가로 인한 도시민의 건 강피해가 발생하기 시작한 것은 1960년대이다. 처음으로 규제되기 시작한 것은 1965년 미국에서 "자동차 오염방지법"의 제정부터이며 1968년부터 자동차 배출가스에 대한 규제가 시작되었다. 한편 일본은 1973년, 유럽에서는 1975년부터 일산화탄소, 탄화수소, 질소산화물 및 매연에 대한 규제를 시작하게 되었다. 우리나라에서는 "도로운송차량법"에서 도로교통의 안전과 질서유지라는 측면에서 일부 규제하여 오다가 1977년말 "환경보전법"이 제정 공포되면서 1980년 1월 환경정의 발족과 함께 실제로 자동차 배출가스를 규제하게 되었다.발족과 함께 실제로 자동차 배출가스를 규제하게 되었다.을 SUP7H종으로 더욱 향상된 것이 실용 화되고 있다. 아래에서 이에 대한 기계적 특성을 중심으로 검토키로 한다.9%내인 0.07cm 정도였으나 1973년과 1974년의 방축년에는 조차 3개 처리구(3.4-5.18cm)에 필적되는 연평균 4.16cm로 나타났다. 5. 전체 시험구로부터으 연평균 토양유실량은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가 있음을 시사한다.se that were all low in two aspects, named "the Nonsignificant group". And the issues were high risk perception in