• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.97-104
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• 2002

The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced

• 동력기계공학회지
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• 제14권2호
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• pp.12-15
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• 2010

It is requested to shorten the starting duration for idle stop function equipped cars without harmful effects on the environment. Higher cranking speeds can be achieved with high torque starter. The object of this study is to develope the high torque starter and evaluate its effect on the exhaust emissions. The test was conducted on a 1.5 L, 4-cylinder, 16 valve, multipoint-port-fuel-injection gasoline engine. Engine out emissions such as HC, CO, $CO_2$, and the excess air ratios, lambda were measured using MEXA-554JK. The result showed that a high torque starter, HTS-II shortened the starting duration and reduced engine out emissions of HC, CO and improved starting performance with larger excess air ratio than that of the original starter, Org. S and a high torque starter, HTS-I.

• 한국대기환경학회지
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• 제6권1호
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• pp.43-50
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• 1990

In the estimation of grid type area source emissions, the factors by which emissions are distributed spatially must be considered comprehensively. The estimation process can be approached systematically by connecting the emission activity of air pollutants with land use pattern and the various impacts can be taken into account in the process by using such area information as land use, population, distribution of households, types of housing units, fuel consumption and so on. The estimation procedure was computerized in order to calculate area source emissions by grid information system. This computerization helped to augment effectiveness and efficiency not only by managing enormous data but also by performing diverse functions.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.449-452
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• 2004

“Flameless combustion” of lean to ultra lean mixtures, supported by high-temperature burned gas, can resolve the dilemma between complete combustion versus ultra-low NOx emissions in gas turbine combustors. The characteristics of NOx emissions and combustion in “lean-lean” two-stage combustion were investigated for fuel vapor and droplets / air mixture jets injected from the main injection tube that was placed perpendicular to the combustor wall into the primary hot burned gas prepared by combustion of lean mixtures on a perforated flame holder. The present results clearly show that the ultra-low NOx combustion supported by the reaction of lean mixtures well mixed with the hot burned gas from the primary stage is much more advantageous in achieving ultra-low NOx emissions while maintaining high combustion efficiency.

• 한국입자에어로졸학회지
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• 제15권3호
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• pp.91-104
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• 2019

In this study, hourly measurements of $PM_{2.5}$ and its major chemical constituents such as organic and elemental carbon (OC and EC), and ionic species were made between January 15 and February 10, 2018 at the air pollution intensive monitering station in Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were collected at the same site and analyzed for OC, EC, water-soluble OC (WSOC), humic-like substance (HULIS), and ionic species. Over the whole study period, the organic aerosols (=$1.6{\times}OC$) and $NO_3{^-}$ concentrations contributed 26.6% and 21.0% to $PM_{2.5}$, respectively. OC and EC concentrations were mainly attributed to traffic emissions with some contribution from biomass burning emissions. Moreover, strong correlations of OC with WSOC, HULIS, and $NO_3{^-}$ suggest that some of the organic aerosols were likely formed through atmospheric oxidation processes of hydrocarbon compounds from traffic emissions. For the period between January 18 and 22 when $PM_{2.5}$ pollution episode occurred, concentrations of three secondary ionic species ($=SO{_4}^{2-}+NO_3{^-}+NH_4{^+}$) and organic matter contributed on average 50.8 and 20.1% of $PM_{2.5}$, respectively, with the highest contribution from $NO_3{^-}$. Synoptic charts, air mass backward trajectories, and local meteorological conditions supported that high $PM_{2.5}$ pollution was resulted from long-range transport of haze particles lingering over northeastern China, accumulation of local emissions, and local production of secondary aerosols. During the $PM_{2.5}$ pollution episode, enhanced $SO{_4}^{2-}$ was more due to the long-range transport of aerosol particles from China rather than local secondary production from $SO_2$. Increasing rate in $NO_3{^-}$ was substantially greater than $NO_2$ and $SO{_4}^{2-}$ increasing rates, suggesting that the increased concentration of $NO_3{^-}$ during the pollution episode was attributed to enhanced formation of local $NO_3{^-}$ through heterogenous reactions of $NO_2$, rather than impact by long-range transportation from China.

• 환경영향평가
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• 제16권1호
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• pp.1-13
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• 2007

This study was carried out to estimate the emission reduction rates for the regional allowable emissions by special measures to achieve the target air quality in Seoul Metropolitan Area (SMA). A modeling system was designed to validate the details in enforcement regulations set up by local governments based on the current status and plans for air quality improvement. Modeling system was composed of meteorological model (MM5), emission model (SMOKE), and air quality model (CMAQ). Predicted results by this system show quiet well not only daily air pollutants concentration but also the tendencies of wind direction, wind speed and temperature. To achieve the target air quality in Seoul Metropolitan Area (SMA), emission allowances are estimated by seasons and regions. Referring to the base year 2002, it was estimated that emission reduction rates to achieve the intermediate goal in 2007 were 14.2% and 16.6% for NOx and $PM_{10}$, respectively. It was also estimated that 52% of NOx and 48% of $PM_{10}$ reductions from the base year 2002 would be required to accomplish the air quality improvement goal of 22 ppb for $NO_2$, and $40mg/m^3$ for $PM_{10}$ in year 2014. To improve $NO_2$ and $PM_{10}$ concentration through emissions reduction policies, it was found that emissions reduction for the on-road mobile sources would be the most effective in SMA.

• 한국대기환경학회지
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• 제33권4호
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• pp.377-392
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• 2017

A set of BFM (Brute Force Method) simulations with the CMAQ (Community Multiscale Air Quality) model were conducted in order to estimate self-contributions and conversion rates of PPM (Primary $PM_{2.5}$), $NO_x$, $SO_2$, $NH_3$, and VOC emissions to $PM_{2.5}$ concentrations over the SMA (Seoul Metropolitan Area). CAPSS (Clean Air Policy Support System) 2013 EI (emissions inventory) from the NIER (National Institute of Environmental Research) was used for the base and sensitivity simulations. SCCs (Source Classification Codes) in the EI were utilized to group the emissions into area, mobile, and point source categories. PPM and $PM_{2.5}$ precursor emissions from each source category were reduced by 50%. In turn, air quality was simulated with CMAQ during January, April, July, and October in 2014 for the BFM runs. In this study, seasonal variations of SMA $PM_{2.5}$ self-sensitivities to PPM, $SO_2$, and $NH_3$ emissions can be observed even when the seasonal emission rates are almost identical. For example, when the mobile PPM emissions from the SMA were 634 TPM (Tons Per Month) and 603 TPM in January and July, self-contributions of the emissions to monthly mean $PM_{2.5}$ were $2.7{\mu}g/m^3$ and $1.3{\mu}g/m^3$ for the months, respectively. Similarly, while $NH_3$ emissions from area sources were 4,169 TPM and 3,951 TPM in January and July, the self-contributions to monthly mean $PM_{2.5}$ for the months were $2.0{\mu}g/m^3$ and $4.4{\mu}g/m^3$, respectively. Meanwhile, emission-to-$PM_{2.5}$ conversion rates of precursors vary among source categories. For instance, the annual mean conversion rates of the SMA mobile, area, and point sources were 19.3, 10.8, and $6.6{\mu}g/m^3/10^6TPY$ for $SO_2$ emissions while those rates for PPM emissions were 268.6, 207.7, and 181.5 (${\mu}g/m^3/10^6TPY$), respectively, over the region. The results demonstrate that SMA $PM_{2.5}$ responses to the same amount of reduction in precursor emissions differ for source categories and in time (e.g. seasons), which is important when the cost-benefit analysis is conducted during air quality improvement planning. On the other hand, annual mean $PM_{2.5}$ sensitivities to the SMA $NO_x$ emissions remains still negative even after a 50% reduction in emission category which implies that more aggressive $NO_x$ reductions are required for the SMA to overcome '$NO_x$ disbenefit' under the base condition.

• Environmental Analysis Health and Toxicology
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• 제24권2호
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• pp.137-148
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• 2009

This study quantitatively investigated the emissions of indoor air pollutants associated with the utilization of air fresheners indoors, and evaluated individual exposure to five specified indoor air pollutants, which were chosen on the basis of selection criteria. An electrically-polished stainless steel chamber (50L) was employed to achieve this purpose. Test air fresheners were selected through three steps: first, on the basis of market sales; second, on the basis on a preliminary head-space study; and lastly, on the basis of emissions of toxic compounds (benzene, ethyl benzene, limonene, toluene, and xylene). The empirical mathematical model fitted well with the time-series concentrations in the environmental chamber (in most cases, determination coefficient, $R^2{\gtrsim}$0.9), thereby suggesting that the empirical model was suitable for testing emissions. The concentration equilibrium appeared 180 min after the introduction of sample air fresheners into the chamber. Both the chamber concentrations of emission rates or factors varied greatly according to air freshener type. It is noteworthy that although benzene, ethyl benzene, toluene, and xylene were emitted from all test air fresheners, their exposure levels were not significant enough to result in any significant health risk. However, certain type of air fresheners were observed to emit significant amount of limonene, which is potentially reactive with ozone to generate secondary pollutants with oxidants such as ozone, hydroxyl radicals, and nitrogen oxides. The exposure levels to limonene associated with the utilization of three air fresheners were estimated to be 13 to 175 times higher than that of other air fresheners. This information can help consumers to select low-pollutant-emitting air fresheners.

• 대한기계학회논문집B
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• 제26권12호
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• pp.1756-1762
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• 2002

To effectively meet current regulations on the exhaust emissions of diesel engine required to control the deterioration of air pollution in the whole world, this study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in IDI diesel engine. A method fur supplying water through the air intake system to reduce the exhaust emissions has been considered with other methods such as water introduction in the form of water-in-fuel emulsion or water injection directly into the combustion chamber, but it has not been studied about the effects of water on the combustion concepts and the characteristics of exhaust emissions in detail until now. In this study, the formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased by increasing water amount.

• 항공우주정책ㆍ법학회지
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• 제26권1호
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• pp.127-145
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• 2011

European Union unilaterally included the emissions from aviation activities into EU ETS on 19 November 2008 by amending Directive 2003/87/EC. According to the Directive all the emissions(mainly against the CO2) from aviation activities shall be subject to the regulation of EU ETS from 2012. For the period from 1 January 2012 to 31 December 2012, the total quantity of allowances to be allocated to aircraft operators shall be equivalent to 97% of the historical aviation emission s. From 1 January 2013, the allowances will be reduced to 95%. The allocation of allowances which may be applied by each operator with free of charge will be reduced from 85% to 82% from 1 January 2012 to 1 January 2013. Since the Directive will affect every country's airline industry more or less, the nations and international organizations respond variously. The controversial focus is that whether EU has the right to unilaterally include the emissions from international aviation activities into EU ETS. This article firstly analyzes the effect caused by EU ETS to China's airline industry, and then studies the legality of the action of EU subject to current positive international law, and finally draws the conclusion that EU enjoys no such right to unilaterally include the emissions from international aviation activities.