• Title/Summary/Keyword: CDPF

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An Experimental Study on Regeneration Characteristics by Variation of Exhaust Gas Temperature, HC and $O_2$ Concentrations on DOC-CDPF System (배기가스의 온도 및 HC와 $O_2$의 조성 변화에 따른 DOC-CDPF의 재생 특성에 관한 실험적 연구)

  • Cho, Yong-Seok;Lee, Seang-Wock;Lee, Jung-Sub;Yoon, Yu-Bin;Park, Young-Joon
    • 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.

An Experimental Study on Regeneration Characteristics of Catalyzed Diesel Particulate Filter with Variation of Exhaust Gas Temperature and Composition (배기가스 온도 및 조성 변화에 따른 CDPF의 재생 특성에 관한 실험적 연구)

  • Cho, Yong-Seok;Lee, Jung-Sub;Yoon, Yu-Bin;Park, Young-Joon;Lee, Seang-Wock
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.8
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    • pp.597-603
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    • 2008
  • The catalyzed diesel particulate filter (CDPF) is widely used for collecting soot from the exhaust gas of diesel engine. However, the CDPF need being regenerated after the soot accumulation. It is important to know characteristics of regeneration for CDPF with variation of exhaust gas temperature and composition. This study presents characteristics of regeneration according to variable exhaust gas composition. Furthermore, the experiment were performed variable gas temperature of CDPF inlet gas at each exhaust gas composition. Test-rig is used to control at each in let gas temperature and composition during regeneration of CDPF. Reaction intensity($I_c$) is used to compare with each result. Experimental results indicated that increased concentration of $NO_x$ and $O_2$ lead to regenerate more greatly. Also, higher temperature of exhaust gas leads to make CDPF cleaner.

De-Ash Characteristics using a Cleaning Agent KOH of CDPF for PM Reduction of Diesel Engines

  • Seo, Choong-Kil
    • Journal of Power System Engineering
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    • v.20 no.1
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    • pp.30-35
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    • 2016
  • The objective of this study is to investigate the physicochemical properties of the catalysts and the feasibility of remanufacturing them after removing ash in CDPF using a cleaning agent KOH. Compared with the carbon oxidation ability of fresh CDPF, that of de-ashed CDPF had an insignificant difference due to the low activation energy of CO and $CO_2$. As ash deposited in CDPF was de-ashed with KOH, it had a practical feasibility on remanufacturing point of view, but washcoat was melted about 26%. Further studies were required for the prevention of washcoat loss.

The Effect of Flow Distribution on Transient Thermal Behaviour of CDPF during Regeneration (배기의 유속분포가 CDPF의 재생 시 비정상적 열적 거동에 미치는 영향)

  • Jeong, Soo-Jin;Lee, Jeom-Joo;Choi, Chang-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.10-19
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    • 2009
  • The working of diesel particulate filters(DPF) needs to periodically burn soot that has been accumulated during loading of the DPF. The prediction of the relation between an uniformity of gas velocity and soot regeneration efficiency with simulations helps to make design decisions and to shorten the development process. This work presents a comprehensive combined 'DOC+CDPF' model approach. All relevant behaviors of flow fluid are studied in a 3D model. The obtained flow fields in the front of DPF is used for 1D simulation for the prediction of the thermal behavior and regeneration efficiency of CDPF. Validation of the present simulation are performed for the axial and radial direction temperature profile and shows goods agreement with experimental data. The coupled simulation of 3D and 1D shows their impact on the overall regeneration efficiency. It is found that the flow non-uniformity may cause severe radial temperature gradient, resulting in degrading regeneration efficiency.

Physicochemical Characteristics of CDPF according to Ash a Cleaning agent (Ash 세정제에 따른 CDPF의 물리화학적 특성)

  • Seo, Choong-Kil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.641-647
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    • 2017
  • In order to meet the stricter emission regulations, the proportion of after-treatments for vehicles and vessels has been increasing gradually. The objective of this study is to investigate the physicochemical properties according to ash cleaning agents of CDPF for Diesel Engines. Penetrating agents with strong penetration into ash and a surfactant component to mix water and oil were prepared properly. The cleaning characteristics of S1 sample were good. Washcoat loss rate of S1 sample was lower by about 2.2% because of less KOH component and lower Na2SiO3 content. Washcoat loss rate of S4 sample with an added KOH and Na2SiO3 components by penetration agents was increased by about 13%. In terms of less than about 13% of CDPF's washcoat loss rate, it was able to reduce the harmful gas components.

Studies on Reforming Gas Assisted Regeneration of Multi-channel Catalyzed DPF (합성가스(Reforming gas)를 이용한 멀티채널 CDPF의 재생 특성 연구)

  • Choi, Kwang-Chun;Chung, Jin-Hwa;Song, Soon-Ho;Chun, Kwang-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.3
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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.

Effect of NO on Catalytic Soot Oxidation in Tight Contact with $Pt/CeO_2$ Using a Flow Reactor System ($Pt/CeO_2$ 촉매와 Tight Contact 한 상태의 Model Soot 산화에 NO가 미치는 영향에 관한 실험적 연구)

  • Lee, Dong-Il;Song, Chang-Hoon;Song, Soon-Ho;Chun, Kwang-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.3
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    • pp.52-56
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    • 2011
  • Active regeneration in CDPF requires $O_2$ which regenerates soot at high temperature. However, small amount of NO can interrupt $O_2$ regeneration in CDPF. To verify this phenomena, soot oxidation experiments using a flow reactor with a $Pr/CeO_2$ catalyst are carried out to simulate Catalyzed Diesel Particulate Filter (CDPF) phenomena. Catalytic soot oxidation with and without small amount of NO is conducted under tight contact condition. As the heating rate rises, the temperature gap of maximum reaction rate is increased between with and without 50ppm NO. To accelerate the $NO_2$ de-coupling effect, CTO process is performed to eliminate interfacial contact for that time. As CTO process is extended, temperature which indicates peak reaction rate increases. From this result, it is found that small amount of NO can affect tight contact soot oxidation by removal of interfacial contact between soot and catalyst.

Overview of the Effect of Catalyst Formulation and Exhaust Gas Compositions on Soot Oxidation In DPF

  • Choi Byung Chul;FOSTER D.E.
    • Journal of Mechanical Science and Technology
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    • v.20 no.1
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    • pp.1-12
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    • 2006
  • This work reviews the effects of catalyst formulation and exhaust gas composition on soot oxidation in CDPF (Catalytic Diesel Particulate Filter). DOC's (Diesel Oxidation Catalysts) have been loaded with Pt catalyst (Pt/$Al_{2}O_3$) for reduction of HC and CO. Recent CDPF's are coated with the Pt catalyst as well as additives like Mo, V, Ce, Co, Fe, La, Au, or Zr for the promotion of soot oxidation. Alkali (K, Na, Cs, Li) doping of metal catalyst tends to increase the activity of the catalysts in soot combustion. Effects of coexistence components are very important in the catalytic reaction of the soot. The soot oxidation rate of a few catalysts are improved by water vapor and NOx in the ambient. There are only a few reports available on the mechanism of the PM (particulate matter) oxidation on the catalysts. The mechanism of PM oxidation in the catalytic systems that meet new emission regulations of diesel engines has yet to be investigated. Future research will focus on catalysts that can not only oxidize PM at low temperature, but also reduce NOx, continuously self-cleaning diesel particulate filters, and selective catalysts for NOx reduction.

Nanoparticles Emission Characteristics of Heavy-Duty CNG Engine with Oxidation Catalyst (산화촉매를 장착한 대형 CNG 엔진의 나노입자 배출특성)

  • Kim, T.J.;Kim, H.N.;Choi, B.C.
    • Journal of Power System Engineering
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    • v.12 no.5
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    • pp.27-33
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    • 2008
  • Natural gas has been considered one of the most promising alternative fuels for transportation because of its abundance as well as its ability to reduce regulated pollutants. We measured emission characteristics of nanoparticles from lean burn H/D(Heavy-Duty) CNG (Compressed Natural Gas) engine equipped with oxidation catalysts. The experiments were carried out to measure the emission and engine performance according to the ESC test cycle. The CO and THC conversion efficiencies on the best catalyst in the ESC test cycle achieved about 91 % and 83 %, respectively. From the measurement by the SMPS, the number of nanoparticles emitted from H/D CNG engine is reduced by about 99 % which is more than that of 2.5 L diesel engine. The particle number concentrations of H/D CNG engine were almost nanoparticles. Nanoparticles smaller than 30 nm emitted from the H/D CNG engine and diesel engine equipped with a CDPF(Catalyzed Diesel Particulate Filter) were quite similar. However, the particles bigger than 30nm from the CNG engine were smaller than the particles from diesel engine equipped with a CDPF. The higher the CNG engine load, the lower the particle number from engine-out, but it increased slightly at full load.

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Experimental Study on the Viscosity Characteristics of Diluted Engine Oils with Diesel Fuel (경유혼입 디젤엔진오일의 점도특성에 관한 실험적 연구)

  • Kim, Chung-Kyun;Kim, Han-Goo
    • Tribology and Lubricants
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    • v.24 no.1
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    • pp.1-6
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    • 2008
  • An experimental study was conducted to evaluate the viscosity characteristics of multi-grade engine oils in which contain diesel fuels. Unused engine oils of SAE 5W40, 10W40 and 15W40 were blended with a diesel fuel ratio of 5%, 10%, and 15%. The viscosity of a diluted engine oil was measured with temperature variation ranging from $-20^{\circ}C$ to $120^{\circ}C$ using a rotary viscometer. The diluted engine oil in which is blended to a diesel fuel plays an important role for decreasing an engine oil viscosity, which may decrease the oil film thickness and a load-carrying capacity. Test results show that the viscosity tends to fall for the increased temperature when engine oil is mixed with a diesel fuel. Especially, the viscosity at a low temperature zone is radically decreased compared with a high temperature zone. Based on the experimental results, the empirical equation that can predict the viscosity of diluted engine oil is expressed in the exponential function with the variation of the temperature and a fuel ratio of diluted engine oil. This equation may be possible to predict the limitation of the oil-fuel dilution rate at the concept design stage of the CDPF system, which doesn't affect the influence of the tribological components.