• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• 한국가스학회지
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• 제26권6호
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• pp.45-51
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• 2022

고정된 점배출원(Point source)에서 배출되는 오염물질을 포집하여 처리하는 기술은 꾸준히 개발되고 있으나, 비산배출원(Non-point source)의 경우 배출원이 다양하고, 일정하지 않아 배출물질 처리기술 및 실효성 있는 배출계수 등을 개발하는 것은 어려운 실정이다. 그렇지만, 비산배출원은 국내 배출량의 약 60%를 차지하고 있기 때문에 배출량 산정방법이 타당하여야 하며 이를 토대로 사업장은 배출저감기술 등을 개발하여야 한다. 이에, 본 연구에서는 배출량이 많은 석유화학업종을 대상으로 현재 사용되고 있는 배출계수의 실효성과 개선 방안 등을 제시하고자 한다. 이를 위하여, 전남 여수 소재 OO회사의 최근 5년간의 LDAR(Leak Detection And Repair)데이터를 분석하여 비산배출원의 배출특성 확인하였다. 그 결과, 유체 성상에 따른 배출 특성의 차이는 없으나 장치의 크기, 제조사별 특성의 차이가 있음을 확인할 수 있었다. 또한, 석유화학 업종에서 적용하는 자체 배출계수가 정유업종에 비해 크게 나타나는 것을 확인하였으며 이에 대한 개선방안 등을 제시하였다. 이러한 연구를 통하여 석유화학업종에 특화된 배출계수를 적용할 수 있으며 사업장 스스로 이를 획기적으로 감할 수 있는 기술을 개발하는데 기여할 것으로 기대한다.

• 대한기계학회논문집B
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• 제22권5호
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• pp.618-626
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• 1998

This paper describes a series of fundamental studies on reflection and emission of weak pressure waves from an open end of a pipe. Acoustical theories which have been employed in the plane pressure waves inside a pipe are applied to the present study. The objective of the present study is to investigate the reflection or emission coefficient of pressure wave at an open end of a pipe, the length of open end correction, and the directivity characteristics of the pressure waves emitted from the pipe. The results show that the reflection coefficient of pressure wave at an open end and the length of open end correction decrease for the wave length of pressure wave to increase. It is also found that the reflection coefficient for a baffle plate at the exit of pipe is larger than that for no baffle plate.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1195-1198
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• 2005

The improvement of efficiency is the one of the most important part in AC PDPs . To achieve high efficiency, high VUV emission efficiency and High ion induces secondary electron emission coefficient are needed. We have measured the emission spectra of vacuum ultraviolet rays and ion induced secondary electron emission coefficient of MgO protective layer in surface discharge AC-PDP with binary and ternary gas mixtures. We have investigated electro-optical characteristics of AC-PDPs to optimum gas mixture for high efficient.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.166-173
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• 2006

This study investigates a heavy duty diesel engine with swept vol. 12.6L, 4cycle-OHC type to verify the effects of the performance and exhaust gas emission according to the variable specifications of both swirl ratio and flow coefficient in inlet port, combustion bowl and fuel injection system. To meet the high BMEP and stringent exhaust emission standard, a turbocharger with wastegate and an intercooler were installed in the engine. Helical port, major design parameters for combustion chamber and electronic fuel injection pump with 1,000bar were reviewed and applied. Confirmation tests were also performed to meet the target value, $NO_x$ 5.0g/kWh and PM 0.1g/kWh of Euro3 exhaust emission legislation. The results of this study show that not only is it effective to use a relatively bigger bowl size for controlling rapid burning condition due to the decreased in-bowl swirl, but also to use a concave cam with double injection rates to decrease $NO_x$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.86-87
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• 2021

As non-road mobile pollutants such as construction equipment are emerging as the main cause of air pollutants emission, construction equipment regulations are gradually strengthening. Research was conducted by correcting the emission coefficient to calculate and predict air pollutant emissions of construction equipment, but it did not reflect site variables such as field and equipment conditions that affect actual emissions. This study derived an Artificial Neural Network emission prediction model based on the actual emission data of excavators and trucks measured at the site and proposed a platform to predict the emission of air pollutants at the site according to the working size and conditions. Through this, it is possible to establish an eco-friendly process plan using a model from the construction plan.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1185-1194
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• 2000

The characteristics of intake port flow and engine performance with swirl ratio variance in a turbocharged D.I. diesel engine were studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. Through these experiments it can be expected to satisfy performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer, NOx and smoke were measured by gas analyzer and smoke meter. The results of steady flow test are as follows; as the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. Also we realized that there is a trade-off that the increase of swirl ratio decreases mean flow coefficient and increases the Gulf factor. And the optimum parameters to meet performance and emission through engine test are as follows; the swirl ratio 2.43, injection timing BTDC 13oCA and compression ratio 15.5.

• 자원ㆍ환경경제연구
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• 제33권1호
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• pp.87-112
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• 2024

이 연구는 2019년 지역산업연관표와 지역별 및 산업별 온실가스 배출량을 추정하여 우리나라 온실가스 배출현황 및 탄소중립을 위한 탄소세 부과의 경제적 효과를 지역별 및 산업별로 분석하였다. 분석결과 제조업 중심의 광역자치도에서 온실가스 배출량, 배출계수 및 배출유발계수가 높게 추정되었다. 동일한 산업일지라 하더라도 온실가스 배출계수가 지역에 따라 다른 것으로 나타났는데, 이는 대분류 기준에 따른 상품 분류, 생산기술의 특성, 생산요소 투입구조의 지역별 차이 등에 기인하는 것으로 추정된다. 한편 탄소세가 부과될 경우 온실가스 배출량이 많은 제조업을 중심으로 생산비용이 상승하고 수요 및 생산이 감소할 것으로 예측되었다. 이에 비해 탄소세 부과가 각 지역에 미치는 영향은 지역별로 차이가 상대적으로 크지 않을 것으로 예측되었는데, 이는 지역별로 산업비중이 달라 탄소세 부과가 지역에 미치는 직접적인 영향이 다를지라도 산업연관효과에 의해 그 차이가 완화되기 때문인 것으로 판단된다. 이처럼 탄소세 부과의 영향은 특정 지역에 집중되지 않고 전 지역에 파급될 것으로 예상되는 만큼 향후 탄소중립 이행과정에서 지자체 간의 긴밀한 협조가 필요할 것으로 생각된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제16회 학술발표회 논문개요집
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• pp.182-182
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• 1999

• 한국물환경학회지
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• 제23권5호
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• pp.740-747
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• 2007

The advanced wastewater treatment plant of leather industry was selected to evaluated with its effluent water quality and statistical characteristics. Most of pollutants removal efficiencies were over 90% as well. And 95% reliability of effluent concentration were 106.8 mg/L of $COD_{mn}$, 72.04 mg/L of TN. However Effluent quality of TN exceeds the regulated limit. The range of coefficient of variation (CV) were between 0.18 and 2.49. Also, coefficient of reliability (COR) were between $0.03(BOD_5){\sim}0.63(COD_{mn})$ and 0.43 in terms of T-N, $Z_{l-a}$(Normalized Percentiles) value were 55.7 and 2.25 in terms of $BOD_5$ and T-N as shown in the following table.