• Title/Summary/Keyword: CDPF

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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.

A Study on a Statistical Modeling of 3-Dimensional MPEG Data and Smoothing Method by a Periodic Mean Value (3차원 동영상 데이터의 통계적 모델링과 주기적 평균값에 의한 Smoothing 방법에 관한 연구)

  • Kim, Duck-Sung;Kim, Tae-Hyung;Rhee, Byung-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.6
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    • pp.87-95
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    • 1999
  • We propose a simulation model of 3-dimensional MPEG data over Asynchronous transfer Mode(ATM) networks. The model is based on a slice level and is named to Projected Vector Autoregressive(PVAR) model. The PVAR model is modeled using the Autoregressive(AR) model in order to meet the autocorrelation condition and fit the histogram, and maps real data by a projection function. For the projection function, we use the Cumulative Distribution Probability Function (CDPF), and the procedure is performed at each slice level. Our proposed model shows good performance in meeting the autocorrelation condition and fitting the histogram, and is found important in analyzing the performance of networks. In addiotion, we apply a smoothing method by which a periodic mean value. In general. the Quality of Service(QoS) depends on the Cell Loss Rate(CLR), which is related to the cell loss and a maximum delay in a buffer. Hence the proposed smoothing method can be used to improve the QoS.

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Experimental Study of Diluted Engine Oil Characteristics by Diesel Fuel (경유가 혼입된 엔진오일의 특성에 관한 실험적 연구)

  • Kim Han Goo;Park Tae Sik;Kim Chung Kyun
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2004.11a
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    • pp.233-236
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    • 2004
  • An experimental study was conducted to evaluate characteristic variation of diluted engine oil by diesel fuel and its effects on engine components. Especially, engine oil was made to have $15\%$ fuel content. To predict existing diesel fuel content in engine oil after test was used the viscosity calibration curve. About $54\%$ percent of diesel fuel in diluted engine oil was distillated by various paths related to reciprocating motion of piston and the rest diesel fuel plays an important role for decreasing engine oil viscosity. Test results show that lowered engine ell viscosity by diesel fuel dilution become a reason of increasing engine elements wear, Therefore, this caused the quantity of blow-by gas to increase and main gallery pressure to decrease.

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A Study on $NO_x$ Reduction in a Light Duty Diesel Vehicle Equipped with a SCR Catalyst (선택적환원촉매를 적용한 중소형 경유차량의 질소산화물 저감 특성 연구)

  • Park, Young-Joon;Hong, Woo-Kyoung;Ka, Jae-Geum;Cho, Yong-Seok;Joo, Jae-Geon;Kim, Hyun-Ok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.5
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    • pp.118-124
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    • 2011
  • To reach the Euro-6 regulations of PM and $NO_x$ for light-duty diesel vehicles, it will be necessary to apply the CDPF and the de-$NO_x$ catalyst. The described system consists of a catalytic configuration, where the CDPF is placed downstream of the diesel engine and followed by a urea injection unit and a urea-SCR catalyst. One of the advantages of this system configuration is that, in this way, the SCR catalyst is protected from PM, and both white PM and deposits become reduced. In the urea-SCR system, the injection control of reductant is the most important thing in order to have good performance of $NO_x$ reduction. The ideal ratio of $NH_3$ molecules to $NO_x$ molecules is 1:1 based on $NH_3$ consumption and having $NH_3$ available for reaction of all of the exhaust $NO_x$. However, under the too low and too high temperature condition, the $NO_x$ reduction efficiency become slower, due to temperature window of SCR catalyst. And space velocity also affects to $NO_x$ conversion efficiency. In this paper, rig-tests were performed to evaluate the effects of $NO_x$ and $NH_3$ concentrations, gas temperature and space velocity on the $NO_x$ conversion efficiency of the urea-SCR system. And vehicle test was performed to verify control strategy of reductatnt injection. The developed control strategy of reductant injection was improved over all $NO_x$ reduction efficiency and $NH_3$ consumption in urea-SCR system. Results of this paper contribute to develop urea-SCR system for light-duty vehicles to meet Euro-5 emission regulations.

Characteristics of Simultaneous Removal of NOx and PM over a Hybrid System of LNT/DPF + SCR/DPF in a Single Cylinder Diesel Engine (단기통 디젤엔진에서 LNT/DPF + SCR/DPF 하이브리드 시스템의 NOx 및 PM 동시저감 특성)

  • Kang, Wooseok;Park, Su Han;Choi, Byungchul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.2
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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.

Experimental Study on the Tribological Characteristics of Diluted Engine Oil by Diesel Fuel (디젤유가 혼입된 엔진오일의 트라이볼로지 특성에 관한 실험적 연구)

  • Kim, Han-Goo;Kim, Chung-Kyun
    • Tribology and Lubricants
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    • v.21 no.4
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    • pp.159-164
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    • 2005
  • An experimental study was conducted to evaluate characteristic variation of diluted engine oils in which contains diesel fuels and its tribological effects on engine components. In this study, diluted engine oils with $10\%,\;15\%,\;and\;20\%$ of initial fuel content rate have been used for measuring the viscosity reduction rate, blow-by gas increment rate, main gallery pressure reduction rate, and fuel content rate in engine oils. These parameters are strongly related to the tribological characteristics of key engine components. The kinematic viscosity of engine oils in which is contained by diesel fuels from $10\%\;to\;20\%$ in oils is decreasing to approximately $54\%$ of initial diluted fuel-oil volume ratios. The experimental results show that the distillated engine oil decrease the viscosity of engine oil and its oil film stiffness, and increase the wear rate of rubbing parts of engine components. Thus we recommend that the containing volume rate of fuels in engine oils should be restricted to $3\~4\%$ for a sophisticated Diesel engine and $5\~7\%$ for a standard one.

Characterization of SCR System for NOx Reduction of Diesel Engine (II) (디젤엔진의 질소산화물 저감을 위한 Urea SCR 시스템 특성 분석 (II))

  • Lee, Joon-Seong;Kim, Nam-Yong
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.11
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    • pp.83-89
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    • 2008
  • The Effect of Space Velocity(SV) on NOx conversion rate was performed to develop NOx reduction after-treatment system. SV is calculated from engine exhaust gas volume and SCR catalyst volume. Found the Urea injection duty of maximum efficiency for NOx conversion if increase SV, NOx Conversion rate is down. Especially, when SV is more than $110,000h^{-1}$, NOx conversion rate decrease suddenly. Same case, if SV is lower than $40,000h^{-1}$, NOx conversion rate is down. Also, the characterization of Urea-SCR system was performed. Three candidate injectors for injecting Urea were tested in terms of 속 injection rate and NOx reduction rate. The performances of SCR catalytic converter on temperature were investigated. The performance of Urea-SCR system was estimated in the NEDC test cycle with and without EGR. It was found that nozzle type injector had high NOx conversion rate. SCR catalytic converter had the highest efficiency at the temperature of $350^{\circ}C$. EGR+Urea-SCR system achieved NOx reduction efficiency of 73% through the NEDC test cycle.

An Experimental Study on Effects of Soot Loading and Mass Flow Rate on Pressure Drop and Heat Transfer in Catalyzed Diesel Particulate Filter (촉매 코팅 DPF의 soot loading과 유량 변화에 따른 압력강하 및 열전달에 관한 실험적 연구)

  • Cho, Yong-Seok;Noh, Young-Chang;Park, Young-Joon;Kim, Duk-Sang
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.72-78
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    • 2007
  • A diesel particulate filter causes progressive increase in back pressure of an exhaust system due to the loading of soot particles. To maintain the pressure drop caused by DPF under proper level, a regeneration process is mandatory when excessive loading of soot is detected in the filter. It is a major reason why the relation between the amount of soot and the pressure drop in a DPF becomes crucial. On the other hand, pressure drop varies with not only the soot loading but also conditions of exhaust gas such as mass flow rate. Therefore, the relation among them becomes complicated. Furthermore, the characteristics of heat transfer in a DPF is another crucial parameter in order for the filter to avoid thermal crack during regeneration period. This study presents characteristics of pressure drop under various conditions of soot loading and mass flow rate in catalyzed diesel particulate filter. This study also shows characteristics of heat transfer in DPF when high temperature gas flows into the filter. Experiments reveal that the soot loading and mass flow rate affect characteristics pressure drop independently. Experiments also indicate that the amount of coating material has little influence on pressure drop with changes in soot loading and mass flow rate. However, increased catalyst coating may lead to the improved heat transfer which is efficiency to reduce thermal stress of the filter.

A review on the Plan for the Further Reinforcement of the NOx Emission Limit for Marine Diesel Engine (선박에서 배출되는 NOx의 배출량 규제에 대한 대응 방안 고찰)

  • Jang M.S.;Kim S. H.;Kang K.S.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.7 no.4
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    • pp.174-179
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    • 2004
  • Domestic marine diesel engine makers reduce the NOx emission mostly by applying low NOx fuel nozzle and injection timing retard. However, it is necessary to develop high efficient technology (EGR, DWI and SCR, etc.) to reduce NOx emission in order to prepare for the further reinforcement of the NOx emission limit. Also, in the near future, IMO will restrict additively THC, PM and CO with NOx. Therefore, domestic engine makers have to prepare for it and the relevant government ministries should give a sufficient support to these technology research and establish or amend the relevant law, which should include the excursion riverboat.

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