• 한국환경보건학회지
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• 제33권1호
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• pp.36-42
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• 2007

Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. In the Heavy Duty Diesel area, the Continuously Regeneration trap has been widely applied in the retrofit market. As the Special act for the improvement of air quality in the capital area, the retrofit program for DPF to used diesel vehicle has progressed favorably and there are currently over 1,000 of these DPF in use in retrofit applications in korea. These DPF comprise a specially formulated Diesel Oxidation Catalyst upstream of a DPF. The $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to evaluate exactly the DPF devices according to the regulation of DPF certificate test procedure for retrofit(ministry of environment(MOE) announcement NO. 2005-16). To do so the understand of that regulation like the standard of PM reduction rate is needed. In this study the test procedure including test cycle and BPT test condition was examined and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and seoul-10 mode test, no defect could be showed.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.556-565
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• 2016

As a result of the enforced control of emission, many devices, including the diesel particulate filter, have been installed in diesel cars to reduce the emission of particulate matters. In this study, a car fire case has been investigated and analyzed. A car fire broke out after the vehicle traveled a distance of 1.4 km from a car service center. The car was provided with DPF cleaning when the DPF warning light came on. After being dismantled in the engine room, the car's engine and gearbox were investigated. The findings showed that the rear part of the DPF metal case was melted and punctured, while the honeycomb filter of the DPF was damaged. The car fire was caused by an overheated DPF associated with inaccurate maintenance practice. Therefore, the responsibility of the fire rested on the car service center that performed the DPF cleaning.

• 한국철도학회논문집
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• 제10권3호
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• pp.343-349
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• 2007

The flow velocity distribution at inlet and exit of a DPF was measured using a Pitot tube and 2-D positioning equipment. An adaptor which was designed for accessing the Pitot tube probe into inlet of the DPF was fabricated with inlet flange of the DPF. The Pitot tube which was mounted in the 2-D positioning machine could access to the inlet of the DPF through the rectangular window of the adaptor. Automation of the velocity measurement at the inlet and exit of the DPF was effectively achieved and measuring time was reduced drastically. The flow velocity distribution at the inlet of the DPF showed parabola shape with maximum velocity near to the center of the DPF, as expected. The velocity distribution at the exit of the DPF showed crown shape, that is, the flow velocity distribution near to the center of the DPF is lower than that at surrounded peripheral region of the DPF.

• 한국분무공학회지
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• 제24권3호
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• pp.122-129
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• 2019

Flow uniformity in aftertreatment system is an important factor in determining uniform catalytic reaction and filtration. In this study, variety types of DOC-DPF system design were analyzed to increase flow uniformity. For this analysis, ANSYS Fluent was used with porous media setup for DOC and DPF. Turbulent flow was modeled by standard $k-{\varepsilon}$ model excepting porous media. Uniformity index was utilized to evaluate the flow uniformity quantitatively. Reference design showed low velocity region because two large vortex were generated before baffle. When radius of DOC-DPF system was increased, exhaust pressure acting on the inlet decreases and velocity distribution was shifted to one side. When inlet pipe was set to axial center of DOC-DPF system velocity distribution was symmetric. However, flow was not dissipated until the front end of DOC and showed higher uniformity index. When the volume of DOC was reduced while fixed volume of entire DOC-DPF system and baffle plate is located downstream of the DOC-DPF system, there was improvement in uniformity index.

• 한국공작기계학회논문집
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• 제16권4호
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• pp.93-100
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• 2007

The flow velocity distribution at inlet and exit of Diesel Particulate Filter(DPF) by fabricating L-shape connector with the DPF was measured using a Pitot-tube and 2-D transverse machine. An adaptor designed for making the Pitot tube probe access to the inlet and exit of the DPF was connected with the inlet and exit flange of the DPF, respectively. The Pitot tube which was mounted in the 2-D positioning machine could access to the inlet and exit of the DPF through the rectangular window of the adaptor. The L-shape connector in the DPF inlet has a flow guide which is a perforated steel pipe. The flow velocity distribution at the inlet of the DPF showed a chaotic velocity distribution which is different from that with a diffuser type connector. The velocity distribution at the exit of the DPF showed a crown shape which is similar to that of the diffuser type connector. The velocity distribution at the exit of DPF showed different patterns according to the air flow rate.

• 대한기계학회논문집B
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• 제33권5호
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• pp.358-364
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• 2009

This paper is to investigate the influence of driving patterns of slow and high speed vehicles on the performance of continuously regenerating diesel particulate filter(DPF) system matched with operating conditions in field application. The DPF performance test for field application was carried out for two identical DPFs installed to slow and high speed vehicles. A slow speed vehicle was selected among local buses which have driving patterns to repeat running and stop frequently, while a high speed vehicle was prepared to have long route of high speed over 60km/h like inter-city buses. In this test, the regeneration performance on the DPF of slow speed vehicle deteriorated because of high soot load index(SLI) in spite of same balance point temperature(BPT) distribution for high speed vehicle. The DPF of slow speed vehicle melted in the end because the rapid increase of back pressure caused high temperature over $1200^{\circ}C$ in the ceramic wall of DPF. The PM components like ash collected to the filter in the DPF were analyzed in order to investigate the cause of the defect and provide an operation performance of DPF system. In the result of the analysis, high levels of lubrication oil ash(Ca, Mg, P, Zn) were detected.

• 한국가스학회지
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• 제19권6호
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• pp.110-115
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• 2015

본 논문에서는 현재 입자상물질 저감장치인 DPF의 문제를 해소하기 위하여 제안된 것으로서, 단일채널내의 배기가스 통로를 양방향 제어하여 연소시 발생되는 배기가스를 효율적으로 정화한다. 1개의 DPF장치를 장착하고 회전형 밸브를 교번제어 하여 DPF 내부에 입자상물질 적층현상으로 인한 배기가스의 내부압력 증가를 피할수 있고, 출력저하 및 연비효율이 떨어지는 등의 문제를 획기적으로 개선하여 고효율의 출력을 유도할 수 있는 입자상물질 정화시스템을 개발한다.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.31-35
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• 2013

Unsteady fluid dynamics analysis of flow characteristics inside a Metal DPF system is done using a commercial CAE software, CFD-ACE+. The time profiles of both temperature and pressure of exhaust gas are given as initial conditions. It was found that the position of connecting pipes and the numbering of exhaust gases did not affect the flow uniformity. The presence of a DPF resulted in the significant flow nonuniformity effect on the flow characteristics at the inlet of the DPF. Present results can be applied to the selection of optimal geometry that produces uniform flow characteristics inside a DPF system.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권1호
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• pp.67-75
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• 2015

Differential pressure sensor for DPF (Diesel Particulate Filter) is the important part of a automobile exhaust system. This device measures the pressure of before DOC and after DPF to determine whether the DPF regenerate. In this paper reliability assessment criteria for DPF differential pressure sensor are established on terms of quality calcification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.147-154
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• 2012

The number of vehicles applied diesel engine are rapidly rising for fuel economy. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced emission regulation. The Diesel Particulate Filter (DPF) system is considered as the most efficiency method to reduce particulate matter (PM) by car makers but also in retrofit market. In recently, various kinds of partial flow DPF are widely used for proper filtration performance and reducing of pressure drop but it is difficult to define the characteristics of these filters because the filtration mechanism is obscure according to the status of these systems. In this paper we investigated the characteristics of cell open type DPF according to the status of filter especially, PM loading. The PM loading mass in the p-DPF are predicted from increase of differential pressure of DPF and the trend of filtration efficiency so that we can measure filtration efficiency and Balance Point Temperature (BPT) of this p-DPF according to PM loading.