• 한국산학기술학회논문지
• /
• 제19권6호
• /
• pp.689-695
• /
• 2018

본 연구는 배기가스 기준을 만족하기 위해 차량에 장착된 배기가스 후처리 장치(DPF)의 재생제어 방안에 대한 것이다. DPF는 배기가스에 포함된 입자상 물질(PM)을 포집하기 위한 필터로 DPF에 포집된 PM은 일정 조건에 이르렀을 때 고온의 배기가스로 연소시킨다. 이러한 과정을 재생(Regeneration)이라 하는데 DPF의 정상적인 성능을 위한 필수 과정이다. 재생이 잘 되지 않을 경우, 차량의 성능저하와 심한 경우 차량의 화재로도 이어질 수 있다. DPF의 재생은 제어로직에 의해 수행되는데 재생제어 로직이 차량의 운용특성을 제대로 반영하지 못한 경우 DPF 재생이 이루어지지 않을 수 있다. 그렇기 때문에 전술차량의 운용특성을 파악하여 DPF가 정상적으로 재생될 수 있도록 하는 것이 매우 중요하다. 본 연구에서는 전술차량의 운용 특성과 DPF의 특성을 분석하여 이에 맞는 DPF의 재생 제어 로직을 추가하고자 한다. 더불어 추가된 재생 제어 로직에 따른 운용 시 발생될 수 있는 추가적인 문제점까지 동시에 개선하고자 한다.

• KSBB Journal
• /
• 제25권1호
• /
• pp.1-10
• /
• 2010

기존 화석연료를 대체할 수 있는 수송연료로서 바이오 디젤은 유해물질 배출을 줄일 수 있어 친환경 에너지로 기대를 모으고 있다. 바이오디젤 관련 기술 개발 방향을 설정하고 제도적 지원을 위해서는 바이오 디젤의 친환경 특성 및 경제성 등에 대한 보다 정량적이고 정성적인 평가가 필요하며, 바이오디젤 생산과정에서 지구 온난화 지수, 에너지소비, 생산비용, 생산기술 및 feedstock에 대한 LCA 분석 연구를 통해 보다 체계적인 환경 및 경제성 평가가 가능하였다. Feedstock에서부터 연료사용에 이르기까지의 바이오 디젤 LCA 평가와 관련한 많은 연구에서 feedstock 생산과정의 온실가스 배출량과 에너지 소비가 전체 환경 및 경제성 평가 수치의 50-80% 범위를 차지하여, 가장 큰 주요 기여 인자가 되었다. 경제성 측면에서는 초임계 메탄올 공정을 이용하여 폐식용유로부터 바이오디젤을 생산하는 과정이 현실적으로, 기술적으로 가장 유리하였다. 향후, 바이오 연료 시장을 보다 확장하고 보다 광범위하게 사용하기 위해서는 바이오디젤의 물성개선을 비롯하여 원료에 대한 식량과의 논쟁을 피하기 위한 지속가능한 원료확보 관련 연구도 수행되어야만 할 것이다.

• 한국대기환경학회지
• /
• 제20권3호
• /
• pp.317-330
• /
• 2004

The Purpose of this study was to develop the P $M_{2.5}$ source Profiles, which are mass abundances (fraction of total mass) of a chemical species in P $M_{2.5}$ source emissions. The source categories studied were soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal-fired power plant, biomass burning, and marine. The chemicals analyzed were ions. elements. and carbons. From this study, soil source had the crustal components such as Si, hi, and Fe. In the case of road dust. Si, OC, Ca, Fe had large abundances. The abundant species were S $O_4$$^{2-}$, C $l^{[-10]}$ , N $H_4$$^{+}$, and EC in the gasoline vehicle and EC, OC, C $l^{[-10]}$ , and S $O_4$$^{2-}$ in the diesel vehicle. The main components were S $O_4$$^{2-}$, S N $H_4$$^{+}$, and EC in the industrial source using bunker C oil as fuel, C $l^{[-10]}$ , N $H_4$$^{+}$, Fe, and OC in the municipal incinerator source, and Si, Al, S $O_4$$^{2-}$, and OC in the coal -fired power plant source. In the case of biomass burning, OC, EC, and C $l^{[-10]}$ were mainly emitted. The main components in marine were C $l^{[-10]}$ , N $a^{+}$, and S $O_4$$^{2-}$.EX> 2-/.

• 한국자동차공학회논문집
• /
• 제19권3호
• /
• pp.138-145
• /
• 2011

Diesel particulate filter (DPF) systems are being used to reduce the particulate matter emission of diesel vehicles. The DPF should be regenerated after certain driving hours or distance to eliminate soot in the filter. The most widely used method is active regeneration with oxygen at $550{\sim}650^{\circ}C$. Syngas (synthetic gas) can be used to lower the regeneration temperature of Catalyzed DPF (CDPF). The syngas is formed by fuel reforming process of CPOx (Catalytic Partial Oxidation) at specific engine condition (1500rpm, 2bar) using 1wt.% $Rh/CeO_2-ZrO_2$ catalyst. The oxidation characteristics of PM with syngas supplied to filter were studied using partial flow system that can control temperature and flow rate independently. The filter is coated with washcoat loading of $25g/ft^3$ $Pt/Al_2O_3-CeO_2$, and multi-channel CDPF (MC-CDPF) was used. The filter regeneration experiments were performed to investigate the effect of syngas exothermic reaction on soot oxidation in the filter. For this purpose, before oxidation experiment, PM was collected about 8g/L to the filter at engine condition of 1500rpm, bmep 8bar and flow temperature of $200^{\circ}C$ Various conditions of temperature and concentration of syngas were used for the tests. Regeneration of filter started at 2% $H_2$ and CO concentration respectively and inlet temperature of $260^{\circ}C$. Filter Regeneration occurs more actively as the syngas concentration becomes higher.

• 한국자동차공학회논문집
• /
• 제16권5호
• /
• pp.147-156
• /
• 2008

As the management of fuel efficiency becomes globally reinforced in attempts to find an environment-friendly vehicle that will operate against global warming, the interest in and the demand for the type of vehicle with a high-efficiency diesel engine using light oil. However, it also emits a greater amount of PM (particulate matter) and NOx than emissions from vehicles using other types of fuels. Therefore, the DME (Dimethyl Ether), an oxygen containing fuel draws attention as an alternative fuel for light oil that can be used for diesel engines since it generates very little smoke. But to develop and compare performance of an electric controlled common-rail DME engine, engine tests requires optimized injection conditions at required engine RPM and engine torque. These injection conditions cannot be set freely and the data configuration through the experimentally repeated application requires much time as well as a significant amount of errors and effort. The object of this study is to configure the basic injection map using the results of the DME engine experiments performed so far. For this, in this study, the functionalization of the required equations were performed along with the basic review of the factors that had influence on the data map. Through this, the information on the injection pressure, injection amount, injection duration, injection timing, etc. under certain operation condition could be obtained.

• Asian Journal of Atmospheric Environment
• /
• 제2권2호
• /
• pp.90-101
• /
• 2008

The chemical compositions of $PM_{2.5}$ and $PM_{10}$ and associated high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) were investigated during winter and summer at a roadside and an urban background site in Saitama, Japan. The average concentrations of $PM_{2.5}$ exceeded the United States Environmental Protection Agency standards during both periods. Carbonaceous components were abundant in both the observed and calculated (by means of a mass closure model) chemical composition of $PM_{2.5}$. Traffic-related pollutants (elemental carbon and high-molecular-weight PAHs) were strongly associated with $PM_{2.5}$ rather than with larger particles. The mass concentrations of $PM_{2.5}$, as well as those of EC and PAHs associated with the particles, at the two sites were strongly correlated. Comparison of our data with source profile ratios indicates that diesel-powered vehicles were probably the main source of the measured PAHs. The PAHs concentrations were affected by meteorological conditions during our study. Our results highlight the need for the establishment of standards for $PM_{2.5}$ in Japan.

• 한국자동차공학회논문집
• /
• 제14권5호
• /
• pp.32-38
• /
• 2006

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogenous charge compression ignition(HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. In addition, this study confirmed the possibility of securing optimum fuel economy emission reduction in the IMEP 8bar range(which could not be achieved with existing partially premixed combustion) through forced charging, exhaust gas recirculation(EGR), compression ratio change and application of DOC catalyst.

• 한국자동차공학회논문집
• /
• 제15권1호
• /
• pp.162-170
• /
• 2007

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. Anew concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogeneous charge compression ignition (HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. And it is investigated that the effects of the engine rpm and load(or A/F) to emission characteristics.

• 한국가스학회지
• /
• 제12권2호
• /
• pp.12-17
• /
• 2008

강화되는 배출가스 규제에 대응하기 위한 대책으로 LPG 차량에 적용되고 있는 제3세대 LPG 연료공급방식인 LPLi(Liquid Phase LPG Injection)은 LPG 연료를 펌프를 이용해서 고압의 액상연료를 공급하는 것이 가장 핵심적인 기술이다. 그러나 LPG 연료의 경우 저점도, 저비등점의 물리적 특성을 갖는 가스연료로서 기존의 가솔린 또는 디젤용 펌프를 사용할 경우 성능 및 효율이 달라질 수 있다. 본 연구에서는 가솔린 연료 펌프의 임펠라 방식을 응용 변형시켜서 LPG연료용으로 개발된 펌프를 이용하여 다양한 온도와 연료조성 조건에서 초기토출성능 및 효율을 파악하고, 기존 펌프의 단점을 극복할 수 있는 펌프방식의 적용가능성 여부를 판단하고자 한다.

• 한국산학기술학회논문지
• /
• 제18권4호
• /
• pp.641-647
• /
• 2017

디젤 엔진은 가솔린기관에 비해 강력한 파워와 연료의 경제성 및 $CO_2$ 배출양이 적어 상용차뿐만 아니라 일반승용차에서도 시장의 수요가 지속적으로 증가하고 있다. 디젤 엔진의 연소특성상 국부적인 고온반응 영역에서 질소산화물과 확산연소 영역에서 입자상물질이 많이 배출되므로 엄격해진 배기규제를 충족시키기 위해서 자동차와 선박등 촉매후처리장치 장착의 비중이 점차 증가하고 있다. 그 중 입자상물질 저감장치로써 입자상물질필터가 장착되어 왔으나 PM중 약 50%가 연료와 엔진오일에서 석출된 재 성분이 침적되면 필터를 손상시키므로 고온의 연소방식이 아닌 세정제를 이용한 제거기술이 절실히 필요하다. 이 연구의 목적은 디젤 엔진용 촉매코팅된 디젤입자상물질필터에 침적된 재를 세정을 함에 있어서 촉매의 물질의 물리화학적인 특성을 연구하는 것이다. 30분 동안 세정제에 담근 S4 샘플은 침투력이 강한 성분으로 인하여 입자들끼리 응집되고 수축되었다. 재에 침투력이 강한 침투제와 물과 기름을 혼합시켜주는 계면활성제 성분이 적절하게 제조된 S1 샘플의 세정특성이 가장 좋았다. 침투제인 수산화칼륨과 규산나트륨 성분이 첨가된 S4 샘플의 와쉬코트 손실률은 약 13%로 증가하였다. 촉매코팅된 디젤입자상물질필터의 와쉬코트 손실률이 약 13% 이하조건에서 유해가스 성분을 저감시킬 수 있었다.