• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.59-66
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• 2010

Around a toll plaza, vehicles do such maneuvers as slow down, stop, and speed up to pay their tolls when they use ordinary toll gates. They can be expected more fuel consumptions compared to the vehicles which use the Hi-pass, a Korean type of Electronic Toll Collection System(ETCS). To measure the exact amount of difference between the two gas consumptions, we equipped a test vehicle with a measurement system and constructed a model toll gate on our test field. Through the field tests on fuel consumptions, we could confirm a 36.7 % of energy saving when the test car used the Hi-pass. Then we projected the result on the total traffic volumes which had used national expressway network for five months from January 2009. Projected to the whole traffic, potential cost savings reached 5.34 billion won. We expect this result be frequently mentioned of to prove the fuel efficiency of the Hi-pass system.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1064-1069
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• 2014

The use of emulsified fuel and EGR (Exhaust gas recirculation) system are effective methods to reduce NOx emission from diesel engines. In general, it is considered that EGR method influences diesel engine combustion in three different ways: thermal, chemical and dilution effect. Among others, the thermal effect is related to the increase of specific heat capacity due to the presence of $CO_2$ and $H_2O$ in inlet air. Meanwhile, emulsified fuel method of utilizing latent heat of vaporization and miro-explosion has been recognized as an effective technique for reducing diesel engine emissions. In this paper, an author studied on combustion and emission characteristics by using emulsified fuel (EF, Light oil : 80% + Water : 20%) and EGR (30% EGR ratio) system. And the effect of fuel injection pattern control was investigated.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.94-102
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• 2015

The high-pass(brand name of Electronic Toll Collection System) utilization trend on the highway continues to grow as 59.4% (by the end of 2013). In this study, we applied the carbon balance method using a fuel chassis dynamometer with the four passenger car classes in order to measure the fuel consumption of the car using the expressway tollgate. We experimented 18 driving mode at general tollgate and high-pass tollgate. As a result, in case of entry/exit toll there were 21.0~56.4ml/veh fuel consumption savings, in case of open toll fuel consumption savings was analyzed as 10.5~28.1ml/veh. In addition, the annual fuel cost savings by virtue of high-pass was 28.2~57.3 billion won at 70% utilization rate, 32.2~65.5 billion won at 80%, 36.2~73.7 billion won at 90% and 40.3~81.9 billion won at 100%.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.20-25
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• 2017

For the HCNG bus using fuel which is the mixture gas of hydrogen and natural gas, the fuel efficiency and $CO_2$ emission characteristics were analyzed based on the WHVC test results and compared with that of the CNG and diesel buses. $CO_2$ emission characteristics were also analyzed by contribution effects such as carbon emission factor and fuel consumption. As a result, the fuel economy of HCNG bus was evaluated to be 11.5% improvement compared to CNG bus, and it was also showed equivalent to diesel bus. In addition, the $CO_2$ emission of HCNG bus was reduced 20.4% and 34.5% compared to CNG bus and diesel bus respectively. It was concluded that the $CO_2$ emission characteristics were influenced by the carbon emission factor depending on fuel composition and the fuel consumption according to the engine performance.

• 한국연소학회:학술대회논문집
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• 1997.06a
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• pp.89-102
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• 1997

대향류 확산 화염의 매연 생성 특성에 대한 실험적 연구가 수행되었으며, 그 결과 에틸렌 ($C_2H_4$)-프로판($C_3H_8$) 혼합 연료의 경우 매연 생성 상승 효과 (synergistic effect)가 관측되었다. 프로판과 에틸렌의 PAH 생성 양상이 상이하게 나타났으며, 소량의 프로판을 에틸렌 확산 화염에 첨가할 경우 순수 연료에 비하여 매연 및 PAH (다중 고리 방향족 탄화수소; polycyclic aromatic hydrocarbon) 생성이 증대되었다. 단조적으로 변화하는 아세틸렌($C_2H_2$) 농도와 단열 화염 온도를 고려할 때, 이러한 결과는 HACA (H-abstraction-$C_2H_2$-addition) 반응만으로는 확산 화염에서의 매연 발생 및 성장을 설명할 수 없음을 의미한다. 수치해석과 실험 결과의 비교로부터 초기 PAH의 생성 과정을 규명하였으며 이 과정에서 C3 화학종의 재결합 반웅이 매우 중요함을 확인할 수 있었다. 또한, 이러한 C3 화학종과 C2 화학종의 상호 보완적인 역할에 의하여 에틸렌-프로판 혼합 연료에서 매연 생성이 증대됨을 밝혔다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.4
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• pp.912-919
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• 1990

본 연구에서는 다중선회연소기의 원리에 기초하여 속도차가 있는 두 공기류의 전단층에 기체연료를 분출하여 연소시키면 연료가 두 공기류 사이에 유입되므로 연료 가 산화제의 접촉면적이 증대되고 또한 난류혼합속도가 큰 영역으로 연료가 유입되므 로 혼합효과가 증대되어 고부하연소에 적절한 방식이 될 것으로 생각하여 동축이중공 기분류중의 난류 확산화염에 대해 그 화염구조를 밝히고 이 화염을 실용연소기에 응용 하기 위한 기초자료를 얻는데 목적이 있다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.29-30
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• 2001

자연에너지원중 태양에너지를 이용한 자갈축열 태양열 온실의 난방에너지 절감효과를 분석하기 위하여 야간에 내부설정온도를 18℃로 했을 때의 자갈축열 태양열 온실과 동일한 제원의 대조온실의 난방연료소비량을 비교하였다. 자갈축열 태양열 온실의 경우 난방초기에는 연료가 대조온실에 비해 약 10%정도 더 소모되었으나 2일이 경과한 후에는 점차 난방연료소비량이 감소하였다(Fig. 2) 이러한 결과는 자갈축열 태양열 온실의 경우 주간에 온실에 투여되는 일사에 의해 축열이 이루어 질뿐만 아니라 야간에 난방을 할 경우에도 축열층의 온도가 설정온도에 도달할 때까지 축열이 이루지기 때문인 것으로 분석되었다 (Fig. 1). 3월 10일부터 3월 15일까지 6일간의 난방연료소비량이 대조온실은 167℃였으나, 자갈축열 태양열 온실은 109℃로써 대조온실에 비해 약 35%정도 난방연료 절감효과가 있는 것으로 분석되었다(Fig. 2). 6일간의 난방 후 자갈축열 태양열 온실에 난방을 중단한 결과 온실외부의 최저기온이 -2.4℃일 때 자갈축열 태양열 온실의 내부최저온도는 14℃를 유지하였으며, 이후 계속 난방을 수행하지 않은 상태에서도 주간에 축열효과로 인하여 최저외기온이 3℃전후일 때 자갈축열 태양열 온실의 내부온도는 15℃를 유지하였으나 대조온실은 5℃ 전후였다. 그리고, 일기온차가 심한 3월말에는 야간설정온도가 18℃인 경우에 자갈축열 태양열 온실의 난방연료소비량이 대조온실에 비해 월등히 적음을 알 수 있었다(Fig. 1, 2). 3월에 자갈축열 태양열 온실의 난방연료소비량은 대조온실에 비해 약 50%이상의 절감효과가 있는 것으로 나타났다./TEX>3.1cm, 2cm$\times$4.2cm 순으로 나타났다. 5. 저고리의 옆길이 곡선에 대한 평가는 진종의 중심인 겨드랑이가 5cm인 것이 가장 우수한 것으로 나타났으며, 그 다음으로 4cm, 6cm, 3cm 순으로 나타났다. 6. 이에 위의 항목들을 종합하여 제작한 연구저고리는 등길이가 28cm, 어깨선 위치는 1.75cm, 깃크기는 5cm$\times$21.5cm, 소매통 크기는 3cm$\times$4.3cm, 옆길이 곡선은 5cm로써 그 형태에 따른 신체적합성에 대한 외관 관능검사 결과로 3.83의 평균값으로 나타났고, 심미성에 대한 외관 관능검사를 항목별 평균치 값으로 종합하면 4.00의 값으로 나타났다. 또한 각 부위별 동작적합성 관능검사는 7가지 동작을 부위별 항목 평균치 결과 3.95의 유수한 저고리로 평가되었다. 본 연구 실험 결과 앞으로도 전통 저고리를 피복함에 있어 외관과 동작적합성이 좋은 저고리를 만들기 위해 지속적 연구가 요청된다. turned back than the Korean women's. Based on the above findings, a torso prototype was developed for the Chinese women by setting the body measurements in reference with their average body measurements plus minimum reserve. The reference lines were set for front/back central line, front/

• Journal of Energy Engineering
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• v.6 no.2
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• pp.212-219
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• 1997

The objective of this study is to investigate the effects light diesel-water emulsified fuel on performance and exhaust emissions of the compression ignition engine. The experimental results of light diesel-water emulsified fuel operation with new type ultrasonic emulsification apparatus as compared with light diesel operation are very positive; maximum 28% reduction of SFC (in the case of 30% of water content), maximum 60% reduction of smoke (in the case of 30% of water content), maximum 79% reduction of CO emission (in the case of 30% of water content). However, comparing light diesel-water emulsified fuel and light diesel in the same engine under the same operating conditions, power and torque were lower in the case of emulsified fuel. In view of the results for the above mentioned, the mixing of water into light diesel in the form of emulsification proved to be the best means for reduction of specific fuel consumption and exhaust emissions of C.I. engines.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.264-270
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• 2008

Most of burning rate models used in hybrid combustion depend solely on oxidizer flux. But this empirical relation can not represent well the important effect of the thermo-chemical properties of solid fuel and thereby requires different value of empirical exponent and constant for each fuel considered. In this study, a new burning rate correlation was proposed using the mass transfer number(B number) which encompasses the thermochemistry effect of solid fuel and the aerodynamic effect caused by the combustion on the solid fuel surface where the effect of aerodynamic property in the mass transfer number was studied. The PMMA, PP, and PE were chosen as fuel, and gas oxygen as oxidizer. The new empirical burning rate expression depending on both the oxidizer flux and the mass transfer number was able to predict the burning rate of each fuel with just a single exponent value and constant, and it was found that the aerodynamic effect on the blowing effect did show a minor effect on the burning rate correlation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.204-210
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• 2016

This paper presents an experimental analysis of the growth and oxidation processes of soot particles generated in an isooctane diffusive laminar flame due to incomplete combustion. The effects of iron-based diagnostics were employed to measure the elastic scattering light from soot particles in a flame at different flame heights, and the differential scattering coefficients were calculated through a calibration process. The growth and oxidation of soot particles in flame was investigated by comparing differential scattering coefficients, and the soot volume fraction was seen to decrease in the soot oxidation process. In the same manner, the differential scattering coefficients were calculated for iron-based fuel-additive seeded flame, and these coefficients were revealed to be smaller than those obtained in the fuel-additive unseeded flame. In addition, transmission through the radial direction of the flame was measured, and transmission in the soot oxidation regime was approximately 5% higher for the seeded flame. The propensity of the data coincided well with the differential scattering coefficients, and it can be concluded that the iron component of the fuel additive plays a crucial role as a catalyst, which eventually enhanced soot particle oxidation.