• 한국자동차공학회논문집
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• 제13권1호
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• pp.60-67
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• 2005

Mild combustion or Flameless oxidation(FLOX) have been considered as one of the most prospective clean-combustion technologies to meet both the targets of high process efficiency and low pollutant emissions. A mild combustor with high air preheating and strong internal exhaust gas recirculation is characterized by relatively low flame temperature, low NOx emissions, no visible flame and no sound. In this study, the Steady Flamelet Approach has been applied to numerically analyze the combustion processes and NOx formation in the mild combustor. The detailed discussion has been made f3r the basic characteristics of mild combustor, numerical results and limitation of the present combustion modeling.

• 한국환경과학회지
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• 제13권4호
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• pp.339-347
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• 2004

This paper asks the question: what choice of environmental policy instruments is efficient to reduce sulfur dioxide from stationary sources\ulcorner: In Korea, command and control has been a common way of controlling $SO_2-emissions.$ When compared to the non-incentive environmental policy instrument such as command and control, economic incentive environmental policy instrument has been the advantage of making polluter himself flexibly deals with in marginal abatement cost to develop environmental technology in the long view. Therefore, the application possibility of the incentive environmental policy instrument was studied in this research to realize the countermeasure for controlling of $SO_2-emissions.$ As a result, enforcement of the countermeasure such as flue gas desulfurizer by command and control would be suitable because power generation is performed by the public or for the public in source of air pollution and thus, economic principle is not applied to the polluter. In the source of industrial pollution, enforcement of fuel tax is found to be suitable for the countermeasure for the use of low sulfur oil in terms of the flexibility of demand for the price in the long tenn. For the permissible air pollution standards applicable to all air pollutant emitting facilities, enforcement of incentive environmental policy such as bubble, off-set, banking policy or tradeable emission penn its would be ideal in long terms according to the regional characteristics and the number and scale of air pollutant emitting facilities.

• 한국분무공학회지
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• 제25권1호
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• pp.27-33
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• 2020

NOx, PN and CO emissions from diesel trucks make up a significant portion of domestic air pollutant emissions. Therefore, test vehicles with various emission standards and driving modes were selected to evaluate the emission characteristics of regulated pollutants (NOx, PN, CO) in medium-duty trucks. As a result of test, all test vehicles were satisfied with Euro 5 or 6 regulation. NOx emissions of Euro 6 vehicles with after-treatment of LNT + DPF were lower than those of Euro 5 vehicles with DPF. In WLTC mode, all vehicles have high NOx emissions at section of extra high speeds, which are determined by increased fuel consumption and high combustion temperatures. CO and PN emissions from all vehicles were found to be low at section of low speeds. Also, The NO₂/NOx ratio was analyzed at 7-23% in each mode, and the NO₂/NOx ratio increased as the average vehicle speed increased. In NIER 9 mode, the CO, HC, and PN emissions were higher under cold conditions of engine than hot conditions of engine. In addition, vehicles with after-treatment system of LNT have similar NOx emissions level in this study.

• 한국대기환경학회지
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• 제34권1호
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• pp.76-86
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• 2018

Using the CAPSS emissions data, we analysed changes and reasons in the annual air pollutant emission trends from 1999 to 2014. The CO emissions in the metropolitan area decreased steadily since 2001, when the latest model year of automobiles and high efficiency fuel were applied. However, other regions have not changed significantly in annual emissions. $NO_x$ emissions continued to increase since 2003, and unchanged after the decline in 2007. $SO_x$ emissions are steadily declining due to the supply of low sulfur oil. The $PM_{10}$ and $PM_{2.5}$ emissions were repeatedly affected by the influence of motor vehicles activities in the metropolitan area. In Gangwon and Chungcheong Provinces, emissions are increasing according to the use of coal in the manufacturing sector. And VOC and $NH_3$ emissions are increasing steadily every year. The major CO emission sources was automobiles in the metropolitan area. However, agricultural residue burning was the biggest CO sources in the Chungchong, Honam and Yeongnam Provinces. The major sources of $NO_x$ emissions differ from region to region. In the Metropolitan area, Honam and Yeongnam region, the truck was the largest emitter of $NO_x$. However, the cement kiln was the largest producer of $NO_x$ in Gangwon region, and the power plant is the largest emitter in Chungcheong Provinces.

• 한국산학기술학회논문지
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• 제15권6호
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• pp.3370-3375
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• 2014

MILD(Moderate and Intense Low Oxygen Dilution) 연소는 열효율 향상과 유해배출가스 저감의 상반된 관계를 해결하기 위한 하나의 각광받는 기술이다. 연소가스의 재순환을 이용하여 고온 연소시에 질소산화물을 낮게 유지함과 동시에 연소로 내부온도를 균일화함으로써 열효율을 향상시킬 수 있는 기술이다. 본 연구는 실험실 규모의 노에서 원추형 MILD 연소기의 연소특성을 나타내고 있다. 연구의 조건은 공기의 유량은 일정하게 하면서 가스 연료 유량을 변화시켜 당량비를 변화시켰다. 이 결과 노 내에서 MILD 연소영역이 잘 구현되었고, 당량비 0.69~0.83의 범위에 걸쳐서 노(爐)내에서의 온도와 배출가스의 농도가 각각 예측되었다. 이 당량비 구간에서 최고화염온도 영역과 주 반응영역에서의 온도차가 약 $300^{\circ}C$의 안정적인 화염 영역의 존재를 확인하였다.

• Environmental Engineering Research
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• 제25권4호
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• pp.522-528
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• 2020

To achieve the clean and efficient utilization of low-rank coal, the combustion and pollutant emission characteristics of chars from low-temperature and fast pyrolysis in a horizontal tube furnace were investigated in a TG-MS analyzer. According to the results, the combustion characteristic of chars was poorer than its parent coals. The temperature range of gaseous product release had a good agreement with that of TGA weight loss. Gaseous products of samples with high content of volatile were released earlier. The NO and NO₂ emissions of chars were lower than their parent coals. Coals of high rank (anthracite and sub-bituminous) released more NO and NO₂ than low rank coals of lignite, so were chars from coals of different ranks. SO₂ emissions of char samples were lower than parent coals and did not show obvious relationship with coal ranks.

• 한국연소학회지
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• 제4권1호
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• pp.85-93
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• 1999

Experimental study on a porous ceramic liquid fuel combustor is performed. Compact burner with low pollutant emission and high combustion efficiency is realized through the use of porous ceramic materials of high porosities. The use of porous ceramic materials in burner material results in rapid vaporization of liquid fuel and enhancement in mixing process, and thus nearly premixed combustion of liquid fuel is achieved instead of diffusion and partially premixed combustion method, which is often used and apt to produce high pollutant emissions such as CO, NOx and soot. With this enhanced vaporization and premixing method of liquid fuel vapor and air, it is found that enhanced combustion process with intense radiation output and better emission characteristics in NOx, CO and soot emission, compared to other conventional liquid fuel burning method, are possible.

• Journal of Advanced Marine Engineering and Technology
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• 제26권1호
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• pp.37-47
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• 2002

Recently gasoline direct injection method has been applied to gasoline engine to reduce fuel consumption rate by controlling fuel air mixture on lean condition by means of stratified charging, and to reduce simultaneously. Pollutant emissions especially NOx and CO by lowering the combustion temperature. But difficulty of controling local fuel air ratio at ignition area in flammability limit unavoidably appeared, because it is merely controlled by injection timing with spatial and temporal distribution of fuel mixture. In this study, the authors devised a uniquely shaped combustion chamber so called three-chamber GDI engine, intended to keep the more reliable fuel air ratio at ignition area. The combustion chamber is divided into three regions. The first region is in the rich combustion division, where the fuel is injected from the fuel injection valve and ignited by the spark plug. The second region is in the lean combustion division, where the combustion gas from the rich combustion division flows out and burns on lean condition. And the last region is in the main combustion division ie in the cylinder, where the gas from the above two combustion divisions mixed together and completes the combustion during expansion stroke. They found that the stable range of operation of three-chamber GDI engine on low-load condition exists in the lean area of average equivalence ratio. And they also found that the reformed engine reveals less specific fuel consumption and less pollutant emissions compared with conventional carburettor type gasoline engine.

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.233-243
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• 2009

The strengthened regulations for atmospheric emissions from ships like MARPOL Annex VI have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. This paper attempts to investigate the configuration of SOFC system for LNG tanker taking into account the safety and to analyze the influence of design parameters on the system performance. The simulation results provide the basic data for the design and efficiency improvement of SOFC system and indicate the guidelines for the safe system operation.

• Journal of Advanced Marine Engineering and Technology
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• 제33권4호
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• pp.484-496
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• 2009

The strengthened regulations for atmospheric emissions from ships like MARPOL Annex VI have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. This paper attempts to investigate the configuration of SOFC/GT hybrid power system for LNG tanker taking into account the safety and to analyze the influence of design parameters on the system performance. The simulation results provide the basic data for the design and efficiency improvement of SOFC/GT hybrid system and indicate the guidelines for the safe system operation.