• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.474-481
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• 2018

The policy-making and technological development of eco-friendly automobiles designed to increase their supply is ongoing, but the internal combustion engine still accounts for approximately 95% of automobiles in use. To meet the stricter emission regulations of internal combustion engines based on fossil fuels, the proportion of after-treatments for vehicles and (ocean going) vessels is increasing continuously. As diesel engines have high power and good fuel economy in addition to less CO2 emissions, their market share is increasing not only in commercial vehicles, but also in passenger cars. Because of the characteristics of the diesel combustion, however, NOx is generated in localized high-temperature combustion regions, and particulates are formed in the zones of diffusion combustion. LNT and urea-SCR catalysts have been developed for the after-treatment of exhaust gas to reduce NOx in diesel vehicles. This study examined the effect of a containing promoter on SCR catalysts to cope with the severe exhaust gas regulation. The de-NOx performance of the Mn-SCR catalyst was the best, and the de-NOx performance was improved as the ion exchange rate between Mn ion and Zeolyst was good and the activation energy was low. The de-NOx performance of the 7Cu-15Ba/78Zeoyst catalyst was 32% at $200^{\circ}C$ and 30% at $500^{\circ}C$, and showed the highest performance. The NOx storage material of BaO loaded as a promoter was well dispersed in the Cu-SCR catalyst and the additional de-NOx performance of BaO was affected by the reduction reaction of the Cu-SCR catalyst. Among the three catalysts, the 7Cu-15Ba/Zeolyst SCR catalyst was resistant to thermal degradation. The same type of CuO due to thermal degradation migrates and agglomerates because BaO reduces the agglomeration of the main catalyst CuO particles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3578-3582
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• 2010

The nitrogen oxidized substance(NOx) from cars in city is one of serious air-polution problems. In advanced country, the powder or the liquid photocatalystic for asphalt pavement and noise barrier have been used to reduce the air-polution. In this paper, the effect of photocatalystic on asphalt pavement has been evaluated, especially for UV optical science reactions analyzed NOx purification efficiencies of the automobile waste gas. Judging from the limited lab-scale test, the use of the powder or the liquid photocatalystic is one of alternatives to reduce the NOx from automobile.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.6
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• pp.628-636
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• 2005

In this paper. the effects of a WI(Water Injection) in the intake pipe for a 4-cylinder Dl(Direct Injection) diesel engine are investigated experimentally, The WI system was controlled by the duty cycle from the intake manifold's temperature and MAF(Manifold Air Flow) First. effect of EGR on NOx reduction was investigated. Then WI system was applied to reduce NOx As the results. we can make the NOx map and visualize the NOx results by variation of engine speed and engine load It was known that effect of WI system on NOx reduction without the EGR was better than the with EGR base engine except of low load and speed condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.57-63
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• 2005

The effects of an urea injection at the exhaust pipe for a 4-cylinder DI(Direct Injection) diesel engine were investigated with the parameters such as urea-SCR(Selective Catalytic Reduction) and EGR system. The urea quantity was controlled by NOx quantity and MAF(Manifold Air Flow). The urea injection quantity can be controlled with the urea syringe pump, precisely. The effects of NOx reduction for the urea-SCR system were investigated with and without ECR engine, respectively. It was concluded that the SUF(Stoichiometric Urea Flow) is calculated and the NOx results are visualized with engine speed and load. Furthermore, the NOx map is made from this experimental results. It was suggested, therefore, that NOx reduction effects of the urea-SCR system without the EGR engine were better than that with the EGR engine except of low load and low speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.778-783
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• 2006

Numerous researches have been conducted to investigate an optimal EGR rate which minimizes emission levels of NOx without increasing PM or loosing an engine power. In this research, the interrelation among engine parameters were intensively investigated and evaluated quantitatively, and proposed some directions in design of a heavy diesel engine by applying EGR and Oxygen-enriched system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.611-614
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• 2008

Urea-SCR system has been known so far as one of effective after treatments for the reduction of NOx. In order to achieve better performance in SCR system, optimal geometric conditions for a urea injection system should be achieved. This research focused to visualize spray characteristics of urea injected SCR system in a heavy duty diesel engine. The experiment was conducted by varying injection pressures and flow rates of urea. The flow visualization was made by photographing techniques of CCD camera.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.521-527
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• 2005

The effects of an urae injection at the exhaust pipe for a 4-cylinder DI(Direct Injection) diesel engine are investigated experimentally. The urea quantity was controlled by NOx quantity and MAF(Manifold Air Flow). The urea injection must be precisely metered and then I used the urea syringe pump. I have tested 4 kinds of items that were with the EGR base engine and without the EGR engine. Then I tested each urea-SCR(Selective Catalytic Reduction) system. As the results, I can caculate the SUF(Stoichiometric Urea Flow) and visualize the NOx results by variation of engine speed and engine load. Also, I can make the NOx map. Therfore, I knew that NOx reduction effects of the urea-SCR system without the EGR engine were better than the with EGR base engine except of low load and low speed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.60-60
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• 2017

화석연료의 고갈과 환경오염이 문제시 되면서 친환경 에너지개발에 대한 연구가 진행되고 있다. 그중 바이오디젤은 동,식물성유지 및 폐식용유를 이용하여 생산이 가능할뿐더러 농용엔진에 특별한 개조 없이 사용가능하다. 또한 바이오디젤 자체에 산소를 함유하고 있어 이산화탄소 저감에 효율적이다. 바이오 디젤에 관한 많은 연구가 수행되었으며, 기존의 연구는 단일유지의 폐식용유를 사용하여 바이오디젤을 생산하는 연구가 진행되었다. 하지만 가정에서 배출되는 식물성 폐식용유의 경우 여러 가지가 혼합되어 배출되고 있어, 혼합폐식용유지의 바이오디젤 특성평가가 필요하다. 따라서 본 연구에서는 폐식물성유지(폐대두유, 폐카놀라유, 폐해바라기유)를 중량비(1:4, 1:1.5 1:0.66, 1:0.25)로 혼합하여 바이오디젤을 생산하고, 생산한 바이오디젤을 농용기관에 이용하여 농용기관의 출력특성 및 배기배출물특성 평가를 실시하였다. 실험에 사용된 농용기관은 배기량이 673cc인 직접분사식 디젤기관(ND10DE, Daedong, Korea)이며, 엔진성능평가를 위해 토크는 토크센서(YDL-704s, Setech, Korea)를 사용하였다. 배기배출물 평가는 배기가스분석기(HG-550, Airlex, Germany)를 이용하여 이산화탄소, 질소산화물을의 배출량을 측정하였다. 폐식용유를 이용하여 생산한 바이오디젤과 경유의 기관성능을 비교한 결과 토크와 축출력의 경우 BD의 혼합량이 증가할수록 줄어들었다. 토크는 혼합된 유지에 따라 상용운전범위인 1500rpm~2400rpm에서 평균 대두와 카놀라유를 혼합하여 생산한 BD10은 7.2%, BD20은 12.1% 감소하였고, 대두와 해바라기유를 혼합하여 생산한 BD10은 11.3% BD20은 16.3% 감소하였다. 또한 해바라기와 카놀라유를 혼합하여 생산한 BD10은 8.3%, BD20은 14.6% 감소하였다. 이는 BD의 발열량이 경유에 비해 낮아 토크가 감소한 것으로 판단된다. 또한 배기배출물 평가의 경우 질소산화물은 BD의 함랑이 증가함에 따라 경유에 비해 배출량이 증가하는 경향을 보였고, 이산화탄소는 저감되는 것으로 나타났다. 이는 바이오디젤이 함산소연료이므로, 연료내의 산소로 인해 완전연소를 촉진시켜 이산화탄소를 저감시키고 질소산화물은 증가된 것으로 판단된다.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.62-71
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• 2015

In order to deal with the globally increasing electric power demand and reduce $CO_2$ emission, complex thermoelectric power plants are being constructed in densely populated downtown areas. As the environmental regulations are continuously strengthened, various facilities like low NOx burner and SCR are being installed to reduce NOx emission. This study is applied using the TMS emission of $NO_2$ from combined heat and power plant located in Goyang-si Gyeonggi-do. Applying data to the computational fluid dynamics(CFD), and compared with the actual measurement results. It is judged that even though there might be differences between actual measurements and CFD results due to the instant changes of wind direction and wind speed according to measurement time during measurement period, modeling results and actual measurement results showed similar concentration at most forecasting areas and therefore, the forecasting concentration could be deducted which is close to actual measurement by calculating the contribution concentration considering the surrounding concentration in the future.

• Fire Science and Engineering
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• v.18 no.2
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• pp.34-40
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• 2004

The effects of external flow excitation with various frequencies and amplitudes on the flame behavior and pollution emission characteristics from a laminar jet flame are experimentally investigated. Measurements of $NO_x$ emission indices ($EINO_x$), performed in vertical lifted flame like turbulent with various exciting amplitude at a constant resonance frequency, have been conducted. It was also conducted to investigate the effects of excited frequency at a constant exciting amplitude on $NO_x$ emissions with a various frequency ranged 0 Hz to 2 KHz. From the vertical lifted turbulent flame of the excited jet with resonance frequency by strong excitation was shown that the dependence of $NO_x$ emission could be categorized into three groups Group I of long flame length with high disturbances yielding high $NO_x$ emission, Group II of intermediate flame length and relative narrow flame volume with low disturbance yielding low $NO_x$ emission and Group III of long flame length and large flame volume with high time ＆ space disturbances behaviour yielding high $NO_x$ emission.