• 대한기계학회논문집B
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• 제28권3호
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• pp.359-364
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• 2004

For the development of high efficiency and low emission combustion systems, high temperature air combustion technology has been tested by utilizing preheated air over 1100 K and exhaust gas recirculation. In this system, combustion air is diluted with large amount of recirculated exhaust gases, such that the oxygen concentration is relatively low in the reaction zone, leading to low flame temperature. Since, the temperature fluctuations and sound emissions from the flame are small and flame luminosity is low, the combustion mode is expected to be flameless or mild combustion. Experiment was performed to investigate the turbulent flame structure and NO$_x$ emission characteristics in the high temperature air combustion focused on coflowing jet diffusion flames which has a fundamental structure of many practical combustion systems. The effect of turbulence has also been evaluated by installing perforated plate in the oxidizer inlet nozzle. LPG was used as a fuel. Results showed that even though NO$_x$ emission is sensitive to the combustion air temperature, the present high temperature air combustion system produce low NO$_x$ emission because it is operated in low oxygen concentration condition by the high exhaust gas recirculation.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.104-110
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• 2003

As exhaust emission standards are more stringent, higher conversion efficiency of automotive catalytic converter is required. In addition, catalytic converter is deteriorated during mileage accumulation of vehicle. Therefore the specification of catalytic converter should be decided in consideration of emission standards and deterioration. Because the decision of the specification of catalytic converter is required at the beginning of vehicle development procedure, it is important and necessary to fix the target values of green vehicle exhaust emissions. To do this, a linear regression analysis was done with in-use exhaust emissions data of 5 different kinds of vehicle that received US94 emission standards certification, and data handling methods including some statistical estimation were proposed. As a result, the fixed target values of NMHC, CO, NOx of green vehicle against US94 emission standards were 0.079, 0.83, 0.116, respectively. And expected in-use deterioration factor of NMHC, CO, NOx were 1.75, 2.02, 1.38, respectively. And also it was blown that even if failure rate is 30% after 80,000km driven, it might be sufficiently safe from emission failure confirmatory test of Korea. It is hopeful to make a database of in-use emissions to increase the confidence in correctness of the calculated target values.

• 한국대기환경학회지
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• 제1권1호
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• pp.83-92
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• 1985

In odrder to survey the emission level of air pollutants from diesel vehicles, was measured CO, HC, NOx and smoke of 4 types of domestic-use diesel engines under various conditions. The emission of CO, HC and NOx tested by 6-Mode test method and smoke emission by full load test met the permissible vehicle emission standard. Pollutant emission rates of diesel engines were different according to engine operating conditions, that is, engine load and engine speed. Generally, CO and HC was emitted more at low load and NOx at high load but the trend was quite different by the type of engines. In exhaust gas, $NO_2$ portion of NOx emission was high, specially at low speed and low load. The correlation equation between CLD(NOx) and NDIR(NO) method of nitrogen of nitrogen oxides analysis was y = 1.10x - 3.48 (y: CLD method) as a result of 6-mode test.

• 수산해양기술연구
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• 제36권3호
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• pp.249-256
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• 2000

In order to investigate the effectiveness of methanol, which has high latent heat of evaporation and oxygen contents, for DI diesel engine performance and exhaust emission, the methanol was injected at the suction port of DI diesel engine. The injector used for test was conventional gasoline engine injector and controlled the quantity of methanol per cycle by the power supply controller which designed specially for injector. The results shown that the maximum pressure point was delayed, the value of maximum pressure was decreased, and the concentrations of both NOx and Soot were decreased, as the methanol injection quantity increased, and also the thermal efficiency of engine injected methanol under the high load condition was similar to no methanol injection but under the medium load condition was decreased within the experimental conditions.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.1-8
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• 2001

It is a present situation that the control on automobile emission is getting more restrictive and also the regulations for emission are changing greatly up to level of those advanced foreign countries. Specially, it has been many years that exhaust gases from gasoline automobile rather than from diesel is the major object concerned by Korea and other countries, and it is strongly required on the reduction techniques on harmful NOx and PM among those compositions. Thus, this research focused on the Exhaust Gas Recirculation (EGR) and the target for this research is heavy-duty turbo-diesel engine with Cooled EGR. Furthermore, this research has been made efforts to accomplish the regulation on emission for heavy duty diesel engine.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.65-69
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• 2001

Research on the development of CNG dedicated engine that has important meaning both as a clean fuel and an alterna- tive energy to reduce the exhaust emission from diesel engine are actively going on these days. In this study, in order to present the direction and application of CNG engine, we tested the CNG engine performance experimented by changing the parameters such as ignition timing, equivalent ratio. The engine performance experimented by changing the parameters such as ignition timing, equivalent ratio. The engine performance and exhaust emission were measured by engine performance model at maximum load condition with increasing the rpm in the range of 1,000∼2,200rpm. Also, the testing engine was heavy-duty CNG dedicated engine with displacement of 11,050cc.

• 한국분무공학회지
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• 제22권4호
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• pp.197-202
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• 2017

The objective of this study is to investigate the effects of low-temperature combustion (LTC) on the correlations of combustion characteristics and reduction of exhaust emissions in a small DI diesel engine with biodiesel fuel. In order to analyze the combustion, exhaust emission characteristics and distribution of nano size particles for biodiesel were investigated. In addition, to evaluate the effect of LTC on the combustion and emission characteristics, 30 and 50% of cooled-EGR rates were investigated. From these results, it revealed that the influence of LTC on the combustion characteristics showed that the ignition delay significantly increased and reduces peak heat release rate of premixed combustion by lowering reaction rate. With 50% EGR and advanced injection timing, soot and $NO_x$ emissions were simultaneously reduced.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.15-21
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• 2003

LPG is considered as one of the most prominent alternative automotive fuels in worldwide. However, conventional mixer system can not meet the emission regulations as the mileage accumulation increased. Recently, much attention is focused on the development of LPG liquid injection fuel systems to increase the engine performance and reduce the exhaust emissions. This study evaluates the LPLi(Liquid Phase LPG injection) engine performance and exhaust emission characteristics using a 3.0 liter LPG engine. The fuel supply system and engine management system were changed from FBM into LPLi to control the precise mixture ratio and optimized spark advance.

• 방사선산업학회지
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• 제11권1호
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• pp.13-18
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• 2017

Recently, the number of PET cyclotrons has increased in Korea. A cyclotron mainly produces $^{18}F$, which is used for the production of [$^{18}F$]FDG, a cancer diagnostic radiopharmaceutical. For radiation protection, the discharge control standard under the Nuclear Safety Act limits the radioactive concentration of $^{18}F$ in the exhaust discharged from a nuclear power utilization facility to below $2,000Bq\;m^{-3}$. However, the radioactive concentration of $^{18}F$ discharged during [$^{18}F$]FDG production at the cyclotron facility at Chosun University is maintained at about $1,500Bq\;m^{-3}$ on average, which is 75% of the concentration limit of the discharge control standard, and temporarily exceeds the standard as per the real-time monitoring results. This study evaluated the performance of the exhaust filter unit of the cyclotron facility at Chosun University by assessing the concentration of $^{18}F$ in the exhaust, and an experiment was conducted on the discharge reduction, where $^{18}F$ is discharged without reacting with the FDG precursors during [$^{18}F$]FDG synthesis and is immediately captured by the [$^{18}F$]FDG automatic synthesis unit. Based on the performance evaluation results of the exhaust filter at the cyclotron facility of Chosun University, the measured capture efficiency before and after the filter was found to be 92%. Furthermore, the results of the discharge reduction experiment, where the exhaust $^{18}F$ was immediately captured by the [$^{18}F$]FDG synthesizer, showed a very satisfactory 94.3% reduction in the concentration of discharge compared to the existing discharge concentration.

• 한국대기환경학회지
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• 제28권4호
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• pp.423-434
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• 2012

This study was carried out to develop for the emission factor of greenhouse gas (GHG) from medium and smallscaled incineration facility using RPF which is considering as a part of renewable energy in UNFCC. The actual concentration of the exhaust gas and the fuel composition of RPF were measured for the calculation of GHG emission factor in RPF incinerators, and were compared with the IPCC guideline. The $CO_2$ and $N_2O$ emission factors by the actual concentration of exhaust gas were $2.3575{\pm}1.0070tCO_2/tRPF$ and $0.0014{\pm}0.0014tN_2O/tRPF$ respectively. Also, $CO_2$ emission factor by the RPF composition was $2.7057{\pm}0.0540tCO_2/tRPF$. The GHG emission factor per energy by the actual concentration was $83.0867{\pm}26.0346tCO_2e/TJ$ which showed higher consistency with the GHG emission factor ($80.3967tCO_2e/TJ$) of waste plastic in the IPCC guideline (2006b). The $CO_2$ and $N_2O$ emission factor calculated in this study is considered as a meaningful data for GHG emission factor of RPF incineration facility because of not being developed in ROK.