• 대한기계학회논문집B
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• 제37권10호
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• pp.911-918
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• 2013

Double cone 버너를 장착한 가스터빈용 EV (Environmental Vortex)버너의 연소 특성과 NO 배출 특성을 수치적으로 조사하였다. NO 배출 저감을 위해 연료와 공기의 혼합 특성을 예측하였다. 혼합도와 NO 배출과의 상관관계를 예측하기 위해 메탄 1단계 화학반응식과 2단계 반응식에 적용하여 연소 해석을 수행하였다. 1단계 반응식을 적용한 결과, 혼합도가 저하된 모델에서 NO 배출량이 약 2% 증가하였으며, 혼합도가 향상된 모델의 경우 cone 상부에서 과다한 고온의 화염 영역이 형성되어 NO가 약 169%나 증가하였다. 2단계 반응식의 경우 첫 번째 모델에서 약 3% NO 배출량이 증가하였으며, 두 번째 모델에서 cone 내부의 고온 영역이 형성되지 않고 NO가 약 5% 감소하였다. 이 결과는, 혼합 특성이 저감된 모델에서 NO가 약 63% 증가하였고, 혼합 특성이 향상된 모델에서 NO가 약 11% 감소한 실험결과와 잘 부합하였다. 정량적인 오차가 있음에도, NO 배출의 정성적 경향성이 유사하므로 2단계 반응식을 적용한 수치해석을 통해 설계 변경 방안을 제시하는 것은 타당할 것으로 판단된다.

• 한국수소및신에너지학회논문집
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• 제18권3호
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• pp.265-274
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• 2007

A study has been conducted to clarify NO emission behavior through preferential diffusion effects of $H_2$ and H in methane-hydrogen diffusion flames. A comparison is made by employing three species diffusion models. Special concerns are focused on what is the deterministic role of the preferential diffusion effects in flame structure and NO emission. The behavior of maximum flame temperatures with three species diffusion models is not explained by scalar dissipation rate but the nature of chemical kinetics. The preferential diffusion of H into reaction zone suppresses the populations of the chain carrier radicals and then flame temperature while that of $H_2$ produces the increase of flame temperature. These preferential diffusion effects of $H_2$ and H are also discussed about NO emissions through the three species diffusion models.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.177-179
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• 2012

This work presents an experimental investigation to study $NO_x$ emissions under stoichiometric air ratio and elevated pressure (2~10bar) in a High Press Combustor(HPC) equiped with double cone burner which was designed by Pusan Clean Coal Center(PC3). Exaust gas temperature and $NO_x$ emissions were measured at the end of the combustion chamber. The $OH^*$ radical concentration and $NO_x$ emission were decreased as a function of increasing ${\lambda}$ generally. On the other hand, $OH^*$ radical concentration and $NO_x$ emission increased with ${\lambda}$ pressure of the combustion chamber. $NO_x$ emissions which were governed by thermal $NO_x$, were highly increased under the elevated pressure, but slightly increased at sufficiently low fuel concentrations (${\lambda}>2.0$).

• 한국대기환경학회지
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• 제13권2호
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• pp.123-135
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• 1997

An air pollutant emission inventory system for the input preparations of photochemical dispersion model was developed. Using the system, anthropogenic emissions as well as biogenic emissions in the Seoul metropolitan area were calculated. Anthropogenic emission by fuel combustion using regional cosumption data, and the laundries and so forth was estimated. The biogenic emission was estimated based upon meteorological data and the distribution of land use type in the study area. The anthropogenic emission of pollutants was highest in Seoul, and the second highest in Inchon. TSP and $SO_2$ were found large quantities during the winter due to increased consumption of heating oil. NOx and THC were emitted without seasonal variation. Among biogenic emissions, PAR was very common while NO was the least common. PAR, OLE, and ALD2 were emitted in large volumes in coniferous forest areas, while ISOP was emitted in deciduous forest areas. Generally, most biogenic emissions increased during daytime, and peaked between oen and two o'clock. Because of strong solar radiation, emission during the summer was high. Biogenic NO emissions were found to be lower compared to anthropogenic emissons, and other VOC was indicated relatively high. In the study area, among biogenic emissions PAR was found to be 3 times, OLE 8 times,and ALD2 12 times more common than among anthropogenic emissions.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.233-234
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• 2014

Lean-rich combustion system was composed both fuel-lean and fuel-rich flame at once. Each of fuel-lean and fuel-rich combustion types to reduce Thermal $NO_x$ and obtain flame stability. This study was confirmed a stability of flame through variation of flame shape that EGR was applied and compared the emission characteristics of EGR lean-rich combustion system to normal premixed combustion system at real condition to review a utility of the system. As a result, emission index of $NO_x$ and CO generated from EGR lean-rich combustion system at global equivalence ratio is 0.85 just half level($NO_x$ 0.31 g/kg, CO 0.08g/kg) compared to the amount generated from normal premixed combustion system at equivalence ratio is 0.78.

• 한국대기환경학회지
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• 제26권1호
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• pp.69-76
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• 2010

While increased use of motor cycles in the recent years for various demands could worsen air quality, only few studies have been conducted on estimation of emission factors and characterization of emissions from motorcycle. In this study, emissions from selected six models of motorcycle based on largest market share and production rate were investigated. To investigate gaseous and carbonaceous air pollutants, such as carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxide ($NO_x$), elemental carbon (EC) and organic carbon (OC), total 124 motorcycles between 2003 and 2007 model year were tested with regulatory driving conditions, such as CVS-40 and CVS-47 mode. These motorcycles were further sub-categorized based on their displacement (< 50 cc, 50~150 cc, and $\geq$ 150 cc), type of stroke (2- and 4 strokes) and model year (2003~2005 and 2006~2007). Tested motorcycles with recent model year (2006~2007) exhibited less emissions of regulatory gaseous and carbonaceous air pollutants compared to old model year (2003~2005). Chemical analysis showed that CO present in highest concentration followed by THC and $NO_x$ for all tested motorcycles. Interestingly, two strokes motorcycle produced higher THC emission but less CO and $NO_x$ than those of four strokes. For all types of displacement and stroke, emission factors (gram per kilometer) of THC and CO except $NO_x$ with recent model year (2006~2007) showed decreased trend compared to old model year (2003~2005). In addition to this, due to mixed combustion between gasoline fuel and lubricant, two strokes motorcycle showed OC > EC emission trend.

• 한국자동차공학회논문집
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• 제22권7호
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• pp.70-75
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• 2014

The experiment was done on traveling at the speed of 20km/h, 60km/h and 100km/h using the performance testing mode for chassis dynamometer. The experimental method were employed to measure the waveform of secondary ignition coil and exhaust emission. In this experiment, the correlation between the secondary waveform coming from ignition coil and exhaust emission were measured in decrepit vehicle. The secondary waveform characterized by the value of effective discharge energy. The following results are obtained by analyzing the data relativity between the effective discharge energy and exhaust emission. The variation rate of effective discharge energy was largest 60km/h, 20km/h, 100km/h velocity in the ordered named. As the vehicle velocity increases, the average variation rate of CO and $NO_X$ decreases and that of HC and $CO_2$ decrease. The value of effective discharge energy, CO, $NO_X$ and fuel consumption is measured badly in case of car with failures in MAP, spark plug and good in case of car with before and after maintenance regardless of vehicle velocities. The value of effective discharge energy is to be nearly parabolic shape as vehicle velocity increases. As the value of effective discharge energy increases, the value of $NO_X$, HC and $CO_2$ decrease, the value of CO increase. The most sensible factors of exhaust emission were CO, $NO_X$, and the small variation factors were HC, $CO_2$.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.111-117
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• 2012

To establish area specific control strategy for ambient ozone in the Seoul Metropolitan Area (SMA), the maximum ozone concentration in each local government district in the SMA were estimated by using the OZone Isopleth Plotting Package for Research (OZIPR) model. The modeling period was June 2000 and the emission inventory data used were from National Institute of Environmental Research (NIER). Except the islands of Incheon, whole Seoul and Incheon areas were volatile organic compounds (VOCs) limited, i.e., decreasing the oxides of nitrogen ($NO_X$) emission alone may increase the maximum ozone concentration upto certain point. In Gyeonggi, 12 areas were VOCs limited while 12 areas were in between VOCs limited and $NO_X$ limited, i.e., decreasing both $NO_X$ and VOCs emission may decrease the maximum ozone concentration. Majority of the estimated ozone values were lower than the measured values. The reason could be inaccuracy in emission inventories and/or transport from other areas. The same calculation was carried out for June 2004 and it was found that Seoul was still in the VOCs limited condition.

• 대한기계학회논문집B
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• 제31권6호
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• pp.539-546
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• 2007

An experimental study was performed to investigate the characteristics of chemiluminescence in a radiant burner, varying the excess air ratio from 0.91 to 1.67 at firing rate 80.5 to 134.2 kW/m2 on $OH^*,\;CH^*,\;{C_2}^*$ in LNG-Air premixed flames. The signals from electronically excited states of $OH^*,\;CH^*,\;{C_2}^*$ were detected using a Intensified Couple Charged Detector (ICCD) camera. The measurements of exhausted emission were made to investigate the correlation between chemiluminescence and emissions. The chemiluminescence intensity was increased with increase of firing rate like characteristics of $NO_x$ emission. $NO_x$ also increased with increase of firing rate and excess air ratio. It is found that offset of firing rate is more dominant excess air ratio $NO_x$ emission. The maximum chemiluminescence intensity occurs near the stoichiometric excess air ratio or lean conditions in case of high firing rate and the maximum intensity occurs rather than rich conditions in case of relatively low firing rate. Amount of $NO_x$ emission is maximum at near stoichiometric excess air ratio, which is chemiluminescence intensity is maximum.

• 한국대기환경학회지
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• 제30권2호
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• pp.150-160
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• 2014

Greenhouse gas (GHG) and Air Pollution (AP) emission inventories have been constructed and estimated independently up-to-date in Seoul. It causes difficulty in GHG and AP integrated management due to a difference in emission inventories. In this study, we constructed GHG and AP integrated emission inventories for direct and indirect sources in Seoul during the year 2010 in Energy activities for estimating GHG and AP emissions were derived from IPCC guideline, guidelines for local government greenhouse inventories, air pollutants calculation manual, and Indirect Emission Factors (IEF) reported by Korea Power Exchange. The annual GHG emission was estimated as 50,530,566 $tonCO_{2eq}$, of which 54.8% resulted from direct sources and the remaining 45.2% from indirect sources. Among direct sources, transportation sector emitted the largest GHG, accounting for 47.3% of the total emission from direct sources. As with indirect sources, purchased electricity sector only emitted 98.6% of the total emission from indirect sources. The annual AP emission was estimated as 283,701 tonAP, of which 85.9% was contributed by the combined AP emissions of transportation and fugitive sectors. Estimation of individual air pollutant showed that the largest source were transportation sector for CO, $NO_x$, TSP, $PM_{10}$ and NH3, non-energy sector for $SO_x$, and fugitive sector for VOCs. This study found some limitations in estimating GHG and AP integrated emissions, such as nonconforming emission inventories between GHG and AP, and no indirect AP emission factor of purchased electricity, and so on. Those should be further studied and improved for more effective GHG and AP integrated management.