• 한국대기환경학회지
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• 제28권2호
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• pp.203-210
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• 2012

The purpose of this study is to evaluate the diesel retrofit program which have been proceeded for the last 7 years in Gyeonggi-do. Diesel retrofit programs in Gyeonggi-do consist of the attachment of DPF (Diesel Particulate Filter), p-DPF (partial-DPF) and DOC (Diesel Oxidation Catalyst), switching to LPG engine, scraping an old cars. Emission reduction by diesel retrofit program was estimated $N_2O$ 8,313.4 ton/year, PM10 3,626.4 ton/year, VOC 8,078.5 ton/year in 2010. The benefit-cost analysis shows that the 964 billion wons of benefits are greater than the 853 billion wons of total costs. Diesel retrofit programs could be one of the most effective measures to improve PM10 concentration in metropolitan area. But retrofit programs also need to be properly maintained by each vehicle.

• 한국분무공학회지
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• 제21권4호
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• pp.223-236
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• 2016

On-road source emissions are major air pollutants and have been associated with serious health effects in Seoul metropolis. Thus, it is of fundamental importance to have an accurate assessment of vehicle emissions in order to implement an effective air quality management policy. As a result, there is a need to overview vehicle emission characteristics of air pollutants. This article discusses vehicle exhaust sampling and chemical analysis, emission characteristics of air pollutants, and emission regulations from passenger cars. The vehicle exhaust sampling and chemical analysis methods were described in particulate matter and gaseous compounds. In this article, chassis dynamometer, measurement instrumentation for nano-particulate matter and carbon compounds analysis device were described. For the gasoline and diesel vehicles, the effective parameters of emissions were average vehicle speed, vehicle mileage and model year. The particle number emissions for diesel nano-particles were sensitive to the sampling conditions. Also, the particle number emissions with a diesel particle filter (DPF) largely reduced rather than those without it. This article also describes different emission characteristics of air pollutants according to biodiesel or bioethanol mixing ratio. The Korean emission standards for passenger cars were compared with those of the US and EU. Finally, the objective is to give an overview of relevant background information on emission characteristics of air pollutants from passenger cars in Korea.

• 한국안전학회지
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• 제35권6호
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• pp.9-14
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• 2020

This study was to compare the sampling efficiencies for monitoring of diesel particulate matter (DPM) using two different sampling methods; In-House PVC cyclone sampling heads and commercial airborne DPM (EC) sampling heads mounted on Dorr-Oliver cyclone heads. Personal exposure levels of DPM, analysed for elemental carbon (EC) were 0.004 - 0.2 mg/m³ for the loader drivers and 0.005 - 0.34 mg/m³ for the specialised mining vehicle (SMV) drivers were similar to previous study results. The highest result (0.34 mg/m³) might be from an irregular production schedule and multiple job tasks requested. The results using the two sampling heads were not significantly different and it is thought that the In-House PVC cyclone with 37 mm quartz filter could be used in place of the commercial sampler as a preliminary screen in place of using the commercial sampler.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.152-160
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• 2016

The market demand for diesel engine tends to increase in general passenger cars as well as commercial vehicles because of its advantages. However, to meet the vehicle emissions regulation which will be more stringent in the future, it is necessary to plurally apply all after-treatment technologies such as diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), lean NOx trap (LNT) and selective catalytic reduction (SCR), and so on. Accordingly, the exhaust after-treatment system for diesel vehicle requires the technology of minimizing the numbers of catalysts by integrating every individual catalysts. The purposes of this study is to develop hybrid exhaust after-treatment device system which simultaneously uses LNT/DPF and SCR/DPF catalyst concurrently reducing NOx and particulate matter (PM). As the results, the hybrid system with $NH_3$ generated at LNT/DPF working as a reducing agent of SCR/DPF catalyst, improving NOx conversion rate, was found to be more excellent in de-NOx performance than that in LNT/DPF alone system.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.168-175
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• 2008

In-use light duty diesel vehicles are considered as one of major sources of particulate emissions in many cities, and the start of the retrofit program for the light duty diesel vehicles is expected in near future in Korea. One of the problems of the retrofit of the light duty diesel vehicles is that the exhaust gas temperature is too low to apply passive regeneration DPF systems. This study introduces a catalytic combustor as a new active DPF regeneration technology. This study shows the principle and characteristics of DPF regeneration by the catalytic combustor and suggests it's proper control method for better regeneration.

• 한국화재소방학회논문지
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• 제32권1호
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• pp.99-107
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• 2018

디젤자동차에는 배기가스 중 미세먼지의 배출을 줄이기 위해 디젤미립자포집필터(DPF)가 설치되어 있다. 그런데 디젤자동차에서 DPF로 인해 화재가 발생하는 사례가 보고되고 있다. 이 논문에서는 디젤자동차의 배기가스 배출 규제 실태 및 배기가스 저감 장치에 대해 알아본 후, DPF로 인한 자동차화재 사례, DPF로 인해 발화된 경우의 특징, DPF와 관련된 자동차화재 발생 요인과 예방대책 및 화재원인조사 시 고려사항에 대해 분석한다. 그리고 자동차화재 조사와 관련하여 DPF로 인한 화재의 입증절차를 제시한다.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.72-79
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• 1998

The goals of this research are to understand the regeneration characteristics in diesel particulate filter(DPF) using the cerium additive and throttling. The effects of throttling duration and spring tension of throttling valve were studied. Measurements were made on a 6 cylinder direct injection diesel engine and included pressure drop, filter inlet temperature, oxygen concentrations, and torque. The major conclusions of this work include; (i) the pressure drop is increased with increase of the engine load and the engine speed; (ii) the inlet temperature of the filter is reached $350^{\circ}C$ with certain engine operating condition which leads to sufficient temperature to regenerate with additive; and (iii) oxygen concentrations in the filter and engine torque during throttling operation are decreased by 2 percent and 36 percent, respectively, which are not critical about regeneration and vehicle operation.

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

• International Journal of Automotive Technology
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• 제3권3호
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• pp.111-115
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• 2002

Suddenly increasing numbers of automobiles result in making worse air pollution problems. In particular, the emissions from automobiles affect badly on atmosphere. Nowadays, research on catalyst converter and filter trap as a modem technology is very active because PM is designated as a major cancer material and stringent regulations on this are necessary and required. The ceramic filter is very efficient in reducing particular materials up to 80-90% and is evaluated as a very efficient after-treatment technology. However, it comes with decreased engine performance due to increased back-pressure occurred by thermal crack. In order to solve these problems, several methods are proposed such as fuel additive, electric heater and burner types. This experimental study has been conducted with equipped and unequipped a ceramic filter on a displacement 11,000cc diesel engine and compared in terms of engine performance and emission. To measure the emission, D-13 mode is applied and measured quantities of the exhaust gases, particularly in CO, HC, PM, and NOx. Therefore, this research is focused on the basic mechanism and characteristics on harmful materials generated by ceramic filter.

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