• 제목/요약/키워드: NOx map

검색결과 25건 처리시간 0.21초

비도로용 디젤엔진의 Urea SCR system 적용을 위한 NO2/NOx ratio 예측모델 개발에 관한 연구 (Development of NO2/NOx Ratio Estimation Model for Urea-SCR System Application on Non-road Diesel Engine)

  • 강석호;김훈명;강정호;박은용;권오현;김대열
    • 한국분무공학회지
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    • 제25권4호
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    • pp.178-187
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    • 2020
  • The current emission regulations, US Tier-4 and EU Stage-V, are only able to satisfy the regulations when all currently mass-produced emission reduction technologies such as EGR, DOC, DPF, and SCR are applied. Therefore, in this study, for the application of the Urea-SCR system to non-road diesel engines, the database was established by measuring the NO, NO2 concentration and calculating the NO2/NOx ratio based on the catalyst temperature and exhaust mass flow rate. Also, based on the measured NO2/NOx ratio data, a mathematical model was proposed to predict the NO2/NOx ratio at SCR catalyst, and the suitability of the model was verified through steady-state and transient mode. As a result of comparing the NO2/NOx ratio measured at the DOC outlet under the steady-state condition to two model values separately, the R2 was 0.9811 for the 3D map model and 0.9303 for the mathematical model. And in the case of the NO2/NOx ratio measured at the DPF outlet, the R2 was 0.9797 for the 3D map model and 0.935 for the mathematical model. It was confirmed that the R2 with the model value of the 3D Map of the mathematical model in the transient mode is 0.957, which shows high reliability.

Off-Road 기계식 디젤엔진의 EGR Map 적용에 따른 배출가스 특성 연구 (A Study on Exhaust Gas Characteristics of Off-road Mechanical Diesel Engine According to EGR Map Application)

  • 김훈명;강정호;한다혜;하형수;정학섭;표수강;안중규
    • 대한기계학회논문집B
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    • 제38권8호
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    • pp.665-670
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    • 2014
  • 최근 대기환경 개선에 대한 관심이 대두되면서 화석연료를 사용 하는 기관에 대한 배출가스 저감 연구가 활발하게 진행 되고 있다. 본 연구는 이러한 저감 기술 중 NOx를 저감하기 위해 가장 많이 적용 되고 있는 EGR system을 Off-road 기계식 디젤엔진에 적용하였을 때 나타나는 배출가스 특성을 파악하기 위하여 진행되었다. EGR system 적용을 위하여 먼저 엔진의 운전영역에 대한 배출가스 특성을 파악하였고, 각각의 엔진회전수 조건에서 다양한 EGR 조건을 적용하여 NOx 저감을 위한 최적 EGR 율을 도출하였다. 이에 따라 수정된 EGR 맵 적용 조건의 엔진 배기 특성에 대해 NRTC 모드를 구현하여 EGR 미적용 조건 및 기존 맵과 비교 및 고찰하였으며, 그 결과로 EGR 미적용 조건 대비 NOx가 약 42% 저감됨을 보였다.

ETC 모드에서 Urea-SCR 시스템의 성능 특성 연구 (Study on the Performance Characteristics of Urea-SCR System in the ETC Test)

  • 함윤영;최동석;박용성
    • 한국자동차공학회논문집
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    • 제18권2호
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    • pp.122-128
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    • 2010
  • To meet the NOx limit without a penalty of fuel consumption, urea-SCR system is currently regarded as promising NOx reduction technology for diesel engines. SCR system has to achieve maximal NOx conversion in combination with minimal $NH_3$ slip. In this study, the performance characteristics of urea-SCR system with open loop control were assessed in the European Transient Cycle(ETC) for heavy duty diesel engine. The SCR inlet temperaure varied in the range of 200 to $340^{\circ}C$ in the ETC cycle. Open loop control calculated the urea flow rate based on the NOx and NSR map which gave for each combination of SCR inlet temperature and space velocity the normalized $NH_3$ to NOx stoichiometric ratio which resulted in a steady-state $NH_3$ slip of 20ppm. During the ETC cycle, the open loop control with the optimized NSR offset achieved NOx reduction of 80% while keeping the average $NH_3$ slip below 10ppm and maximum 20ppm. It was also found that NOx sensor was cross-sensitive to $NH_3$ and a control strategy for cross-sensitivity compensation was required in order to use a NOx sensor as feedback device.

소형 디젤 엔진용 배기 재순환용 전자식 밸브에 관한 연구 (A Study on the Electronic-ECR Valve for Light Duty Diesel Engine)

  • 송창훈;이민호;정용일;차경옥
    • 한국자동차공학회논문집
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    • 제11권4호
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    • pp.37-43
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    • 2003
  • The exhaust gas recirculation (EGR) is needed for one of various strategies to reduce NOx emission. But to get the proper EGR rate, the intake and exhaust system become complicated, also application of EGR system is difficult because of the penalty in fuel consumption and the increase in particulate matter. This study is focused on the development of EGR valve using the electrical method. The effects of EGR on the characteristics of NOx, CO, CO2 emissions and particulate mater have been investigated using small-displacement size 0.8-liters engine of diesel passenger car operating at several loads and speeds. After the analysis and comparison between conventional E-EGR valve and developed E-EGR valve performance by test bench, the estimation of vehicle application was executed through the EGR map and CVS-75 test result measured on the chassis dynamometer.

자기조직화지도를 이용한 추진시스템의 전력부하분석 연구 (Study on Load Analysis of Propulsion System using SOM)

  • 장재희;오진석
    • 한국해양공학회지
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    • 제33권5호
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    • pp.447-453
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    • 2019
  • Recently, environmental regulations have been strengthened for SOX, NOX, and CO2, which are ship exhaust gases. In addition, according to the 4th Industrial Revolution, research on autonomous ship technology has become active and interest in electric propulsion systems is increasing. This paper analyzes the power load characteristics of an electric propulsion ship, which is the basic technology for an autonomous ship, in terms of energy management. For the load analysis, data were collected for a 6,800 TEU container ship with a mechanical propulsion system, and the propulsion load was converted to an electric power load and clustered according to the characteristics using a SOM (Self-Organizing Map). As a result of the load analysis, it was confirmed that the load characteristics of the ship could be explained by the operation mode of the ship.

Ginsenoside Rg1 attenuates cerebral ischemia-reperfusion injury due to inhibition of NOX2-mediated calcium homeostasis dysregulation in mice

  • Han, Yuli;Li, Xuewang;Yang, Liu;Zhang, Duoduo;Li, Lan;Dong, Xianan;Li, Yan;Qun, Sen;Li, Weizu
    • Journal of Ginseng Research
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    • 제46권4호
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    • pp.515-525
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    • 2022
  • Background: The incidence of ischemic cerebrovascular disease is increasing in recent years and has been one of the leading causes of neurological dysfunction and death. Ginsenoside Rg1 has been found to protect against neuronal damage in many neurodegenerative diseases. However, the effect and mechanism by which Rg1 protects against cerebral ischemia-reperfusion injury (CIRI) are not fully understood. Here, we report the neuroprotective effects of Rg1 treatment on CIRI and its possible mechanisms in mice. Methods: A bilateral common carotid artery ligation was used to establish a chronic CIRI model in mice. HT22 cells were treated with Rg1 after OGD/R to study its effect on [Ca2+]i. The open-field test and poleclimbing experiment were used to detect behavioral injury. The laser speckle blood flowmeter was used to measure brain blood flow. The Nissl and H&E staining were used to examine the neuronal damage. The Western blotting was used to examine MAP2, PSD95, Tau, p-Tau, NOX2, PLC, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging was used to test the level of [Ca2+]i. Results: Rg1 treatment significantly improved cerebral blood flow, locomotion, and limb coordination, reduced ROS production, increased MAP2 and PSD95 expression, and decreased p-Tau, NOX2, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging results showed that Rg1 could inhibit calcium overload and resist the imbalance of calcium homeostasis after OGD/R in HT22 cells. Conclusion: Rg1 plays a neuroprotective role in attenuating CIRI by inhibiting oxidative stress, calcium overload, and neuroinflammation.

차량용 소형디젤엔진의 배기 재순환용 전자식 밸브 특성과 적용에 관한 연구 (A Study on the Characteristics and Application of E-EGR Valve for Light Duty Automotive Diesel Engine)

  • 송창훈;정용일;차경옥
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권4호
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    • pp.425-431
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    • 2002
  • In this study the characteristics of E-EGR valve developed by electrical method were analysed and the feasibility of application to vehicles was evaluated. The engine of smart car applied for diesel passenger car of small-displacement size developed by common vehicle was used for this experiment. It was installed a 3-cylinder, $0.8\ell$, turbo-charged light duty diesel engine with an electronic EGR valve. After the analysis and comparison of E-EGR valve performance by test bench, the estimation of vehicle application was executed through the EGR map and CVS-75 test result measured on the chassis dynamometer.

소형디젤엔진의 배기가스 재순환용 전자식 밸브의 특성해석 및 차량적용 평가 (Evaluation of E-EGR Valve for Light Duty Diesel Vehicle)

  • 송창훈;이진욱;정용일;양갑진;이창훈;이현우;차경옥
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2001년도 제23회 KOSCO SYMPOSIUM 논문집
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    • pp.185-192
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    • 2001
  • In this study the characteristics of E-EGR valve developed by UNICK were analyzed and the feasibility of application to vehicles were evaluated. Smart car(3L/100km, cdi version) and engine which is small-displacement size, 0.8-liter, of diesel passenger car developed from Mercedes-Benz were used for this experiment. It was installed a 3-cylinder turbo-charged light duty diesel engine with an electronic EGR valve. After the analysis and comparison of E-EGR valve performance under test benchs, the estimation of vehicle application was executed through the EGR map and CVS-75 test result measured on the chassis dynamometer.

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4기통 커먼레일 DME 엔진의 분사조건 보정방법에 대한 연구 (Research on the Injection Condition Calibration Process of a Common-rail DME Fueled Engine)

  • 정재우;강정호;김남호;정수진;이호길;강우
    • 한국자동차공학회논문집
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    • 제16권5호
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    • pp.147-156
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    • 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.

저선회 연소기에서 합성천연가스(SNG) 연료의 수소함량에 따른 연소 특성 연구 (A Study on the Combustion Characteristics with Hydrogen Contents of SNG Fuel in Low-Swirl Combustor)

  • 정황희;강기중;이기만
    • 한국수소및신에너지학회논문집
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    • 제28권2호
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    • pp.181-189
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    • 2017
  • This paper describes experimental results on combustion characteristics with hydrogen contents of synthetic natural gas (SNG) in low swirl combustor. To investigate the effect of hydrogen contents for premixed SNG flame, stability map, CH chemiluminescence images, flame spectrum analysis and emission performances were measured. In the results, as the hydrogen content was increased, the lean flammable limit was expanded and the flame length was decreased. The hydrogen contents affected the flame liftoff height, and it has different tendency according to the equivalence ratio and flame shape. The change of height and length of flame according to hydrogen contents is caused by the fast burning velocity of hydrogen, which can be confirmed by GRI 3.0 reaction mechanism in PREMIX code. The intensity of $OH^*$, $CH^*$ and $C_2^*$ was confirmed by spectrum analysis of flame. As a result, the $CH^*$ intensity was not significantly different according to hydrogen content. The increase of hydrogen contents influenced positively CO and NOx emission performances.