• 산업기술연구
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• 제26권A호
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• pp.39-46
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• 2006

As an automobile fuel, LPG has many environmental advantages compared to gasoline or diesel. However, current LPG engine which is provided with LPG fuel as gas form has lower power and worse fuel efficiency than gasoline engine. These problems of low power and bad fuel efficiency come from lower volumetric efficiency. Also there is a new rising problem of high failure ratio in an engine emission test. Although there are many factors which affect engine performance of exhaust gas emission, one believes that the fact that ECM of gasoline engine is used for LPG engine when retrofitting gasoline engine to LPG engine is one of the main problems, which lower engine power and emit more noxious gas due to wrong ignition timing. To solve these problems, one studied the effects of ignition timing on the exhaust gas to find out the optimum condition of ignition timing. The experimental results show that noxious exhaust gas is reduced and engine power is increased if the optimum control of ignition timing is applied in accordance to the revolution speed of engine.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.149-156
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• 2006

This paper investigates the steady state combustion characteristics of LPG homogeneous charge compression ignition(HCCI) engine with variable valve timing(VVT) and dimethyl ether(DME) direct injection, to find out the benefits in exhaust gas emissions. VVT is one of the attractive ways to control HCCI engine. Hot internal residual gas which is controlled by VVT device, makes fuel is evaporated easily, and ignition timing is advanced. Regular gasoline and liquefied petroleum gas(LPG) were used as main fuel and dimethyl ether(DME) was used as ignition promoter in this research. Operating range and exhaust emissions were compared LPG HCCI engine with gasoline HCCI engine. Operating range of LPG HCCI engine was wider than that of gasoline HCCI engine. The start of combustion was affected by the intake valve open(IVO) timing and the ${\lambda}TOTAL$ due to the latent heat of vaporization, not like gasoline HCCI engine. At rich operation conditions, the burn duration of the LPG HCCI engine was longer than that of the gasoline HCCI engine. CAD at 20% and 90% of the mass fraction burned were also more retarded than that of the gasoline HCCI engine. And carbon dioxide(CO2) emission of LPG HCCI engine was lower than that of gasoline HCCI engine. However, carbon oxide(CO) and hydro carbon(HC) emission of LPG HCCI engine were higher than that of gasoline HCCI engine.

• 대한안전경영과학회지
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• 제17권3호
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• pp.331-341
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• 2015

Gasoline prices vary across Korea. Some gas stations charge higher prices, while others charge lower prices. In this paper, we try to find: why gasoline prices differ markedly across regions. We empirically estimate the determinants of gas prices by incorporating supply side factors as well as demand side factors into the empirical model. Empirical results show that both location-specific factors and store-specific factors affect gas prices. Concentration of competing stores, store brands, ownership of gas stations, and self-service availability influence gas prices. In addition, the availability of other customer services such as convenience stores, car wash, and auto repairs affects gas prices.

• 한국안전학회지
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• 제25권4호
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• pp.13-18
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• 2010

To investigate electrostatic ignition hazards of commercial gasoline used in the gas station, experiments were conducted dealing with the minimum ignition energy(MIE) of several kinds of gasoline under the various temperature. The conductivity of gasoline that was required for an accurate risk assessment as well as the MIE were also examined. The solvent ignitability apparatus which can heat up the inside of the vessels up to $210^{\circ}C$ was used in this study. Four kinds of premium gasoline and four kinds of regular gasoline, differing with respect to the companies, were used as test specimens. The following results were obtained: (1) all gasoline specimens were so sensitive that even an electrostatic discharge with a very low energy, such as about 0.5mJ, could ignite them. The ignitability of premium gasoline was constant irrespective of the companies. On the other hand, the ignitability of regular gasoline was variable depending on the company. (2) The MIE of all specimens depended markedly on the temperature; in other words, an increase in temperature decreases the ignition energy value. (3) The conductivity values of all specimens were low. Those must be taken into consideration in electrostatic risk assessment.

• 대한기계학회논문집
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• 제16권1호
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• pp.175-179
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• 1992

본 연구에서는 LPG 기관을 천연가스 이용기관으로 변경하고자 할 때 발생하는 출력 감소를 보안하기 우하여, 공기연료 혼합비 조절, 점화시기조절, 과급효과 방법에 의한 출력향상 효과를 파악하였다.

• 한국가스학회지
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• 제13권3호
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• pp.54-60
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• 2009

산업의 발달에 따른 영향으로 에너지수요가 증가함에 따라 국내에는 에너지 산업시설(저장시설, 고압가스 배관, 충전소, 탱크로리 등)이 전국에 산재하게 되었고 사용하는 에너지의 종류도 과거 한정된 자원이 아닌 다양한 에너지원을 사용하게 되었다. 이러한 에너지시설에는 화재, 폭발 및 유독물질 누출 등 중대사고가 발생할 수 있다. 더욱이 국내의 에너지시설은 밀집되어 있어 연쇄적인 사고가 일어날 가능성이 존재한다. 이 연구에서는 기존에 설치 운영되고 있는 LPG(liquefied petroleum gas) 및 가솔린(gasoline) 충전소와 LNG(liquefied natural gas) 충전소에 대한 피해예측을 실시하고 이를 비교 분석 함으로써 국내에서 처음 시도되고 있는 가솔린 주유소 및 LPG/LNG 충전소가 병설되어 설치되는 경우의 안전성을 검토하고자 한다.

• 아태비즈니스연구
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• 제14권1호
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• pp.351-364
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• 2023

Purpose - This study examines the effects of Dubai oil price and the volatility on the asymmetry of domestic gasoline price adjustment. Additionally, the study investigates the effects of "Altteul" gas-station and tax-cut policies on asymmetry. Design/methodology/approach - Firstly, the study calculates proxies for asymmetry and volatility of each window(every 3-month) by error-correction model and GARCH(1, 1) using daily domestic gas price and Dubai oil price from 2008/04/15 to 2022/12/31. Secondly, the study investigates the effects of the increasing rate of Dubai oil price, volatility, "Altteul" gas-station and tax-cut policies on asymmetry. The autoregressive distributed lag regression model is employed for estimations. Findings - The study finds that changes in the increasing rate of Dubai oil price and both types of volatility of Dubai oil price increase asymmetry. While "Altteul" gas-station and tax-cut policies decrease asymmetry. Additionally, the study fails to find that asymmetry in the Korean gasoline market in the estimation with total observations. Research implications or Originality - An increase in Dubai oil price volatility means an increase in cost uncertainty for gas-station owners. Since cost uncertainty is a kind of financial risk, the increase in volatility reinforces the asymmetry. The study provides supporting evidence for the idea.

• 동력기계공학회지
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• 제12권4호
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• pp.12-17
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• 2008

The purpose of this study is to analyse and compare the fuel combustion characteristics between LPG and gasoline on SI engine. Pressures of combustion chamber were measured on the state that engine speed was 2000rpm and BMEP was 2.0bar And we measured pressures of combustion chamber regarding variation of the MBT We could know that the combustion pressure of LPG fuel use engine is appeared lower than that of gasoline fuel use engine. At the lean mixture ratio area we could blow that Ignition timings are pulled very forward, and ignition timing of LPG fuel is advanced to $5\sim12^{\circ}$ CA than gasoline fuel. We learned that the value of coefficient of variation of LPG fuel is higher than gasoline fuel.

• 한국대기환경학회지
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• 제17권3호
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• pp.233-240
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• 2001

The composition of volatile organic compounds (VOCs) was anlyzed for major emission sources such as vehicle exhaust, gasoline and diesel vapor, organic solvent vapor, and butane fuel gas. Low carbon-numbered hydrocarbons were found to be the dominant components of gasoline vehicle exhaust. In gasoline evaporative vapor, the predominant constituents were found to be butane and iso-pentane regardless of ambient air temperature. In case of diesel evaporative vapor was similar to those of gasoline evaporative vapor. The composition of organic solvent vapor from painting, ink and petroleum consisted mostly or aromatic compounds such as toluene and m, p, o-xylene. The hydrocarbon fraction of butane fuel gas. which is used by portable bunner, consisted mainly of propane (34%) and butane(70%).

• 대한기계학회논문집B
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• 제36권3호
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• pp.335-342
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• 2012

자동차배출가스는 이산화탄소($CO_2$)에 의한 지구온난화 및 탄화수소(HC)와 질소산화물($NO_x$)에 의한 오존 생성을 야기하는 등, 인체와 환경에 나쁜 영향을 미치기 때문에 이에 대한 관심이 증폭되고 있다. 가솔린 직접분사 (Gasoline Direct Injection; GDI)엔진은 디젤엔진과 같이 연소실내에 연료를 직접 공급하는 방식으로서 가솔린엔진의 취약점으로 지적되어 오던 높은 연료소비율 문제를 획기적으로 개선할 수 있는 기술로 평가되고 있다. 본 연구에서는 분무유도방식(Spray-guided type)의 GDI엔진을 이용하여 공기과잉률 2.0 이상의 초희박 연소를 통해 연료소비율을 개선하였다. 추가적인 연료소비율 개선 및 배출가스 저감을 위해 희박연소시 다단 분사전략과 Exhaust Gas Recirculation (EGR)을 적용하였다. 배출가스 수준과 운전성능을 평가하고 이를 배출가스 규제와 비교 검토함으로써 국내 관련기술 개발 방향 및 상용화 가능성에 대해 검토하고자 하였다.