• International Journal of Automotive Technology
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• v.5 no.4
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• pp.239-245
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• 2004

It has been recognized that alternative fuels such as Liquid Petroleum Gas (LPG) show less polluting combustion characteristics than diesel fuel. Furthermore, engine performance is expected to be nearly equal to that of the diesel engine if direct-injection stratified-charge combustion of the LPG can be adopted in the spark-ignition engine. However, spray characteristics of LPG are quite different from those of diesel fuel. understanding the spray characteristics of LPG and evaporating processes are very important for developing efficient and low emission LPG engines optimized in fuel injection control and combustion processes. In this study, the LPG spray characteristics and evaporating processes were investigated using the Schlieren and Mie scattering optical system and single-hole injectors in a constant volume chamber. The results show that the mixture moves along the impingement wall that reproduced the piston bowl and reaches in ignition spark plug. LPG spray receives more influence of ambient pressure and temperature significantly than that of n-dodecane spray.

• Korean Journal of Pharmacognosy
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• v.21 no.3
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• pp.235-238
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• 1990

Fatty acids, sterols and amino acids were confirmed from seeds of Acanthopanax senticosus for. inermis Harms. Fatty acids were isolated from petroleum ether extract and identified by gas liquid chromatography. Its composition was myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and behenic acid. The composition of sterols that isolated from n-hexane extract were determined by GC/MS. It was confirmed to be a mixture of ${\beta}-sitosterol$ and stigmasterol. And several kinds of amino acids-cysteic acid, threonine, serine, proline, glutamic acid, glycine, alanine, valine, isoleucine, leucine, histidine, lysine and arginine-were confirmed from water fraction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.4
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• pp.266-274
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• 2008

The need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as Liquefied Petroleum Gas(LPG) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to apply it for the conventional gasoline or diesel fuel pump directly. In this study, experiments are performed to get performance and efficiency of the fuel pump at different condition as temperature, rotating speeds, composition of fuel. The characteristics of fuel pump is affected by cavitation due to the variation of temperature and composition.

• Journal of ILASS-Korea
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• v.7 no.2
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• pp.16-21
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• 2002

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. This study addresses the analysis of the LPG spray behavior near injection nozzle. The LPG spray photographs are compared with sprays of diesel fuel at the same conditions. The LPG spray photos show that the dispersion characteristic depends very sensuously on the ambient pressure soon after injection. The spray angle is very wide in a low ambient pressure condition until the saturated pressure at this test condition, but the angle value is quickly reduced at the condition over the pressure.

• Journal of ILASS-Korea
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• v.29 no.1
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• pp.7-15
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• 2024

This study investigates the performance of 2.0L hybrid vehicles equipped with Liquefied Petroleum Gas (LPG) fuel engines, using energy flow analysis. By incorporating a direct LPG injection system (LPDi), the research aims to overcome the reduced maximum output commonly associated with LPG engines. Moreover, the integration of a hybrid system is explored as a means to enhance vehicle fuel economy while reducing CO₂ and emissions. The study employs data from FTP-75 and HWFET driving cycle to inform future research efforts focused on predicting CO₂ emissions and fuel economy for Hybrid Electric Vehicles utilizing LPG Direct Injection. The findings offer insights into optimizing fuel systems for better environmental and operational performance in hybrid vehicles.

• Fire Science and Engineering
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• v.21 no.3
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• pp.78-83
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• 2007

Diesel, a kind of petroleum, which is used in vehicles, vessels, boilers etc causes great damage when a fire happens, because it has higher caloric value than gasoline or kerosene has at burning. Therefore, pool fire experiment was carried using diesel which is sold on the gas station and radiation heat flux that occurs from flame and inner temperature of flame at burning was estimated. The maximum instantaneous flame temperature of diesel was more than $900^{\circ}C$, and the average of maximum flame temperature was $800^{\circ}C$ which occurred at 0.5 H/D distance from the surface of inflammable liquid, the distance has more long that has the lower the temperature of flame. In case of radiation heat flux, it grew to vary according to the size and amount of sample. When the size of a container for experiment was 0.5 m and sample layer was 13 mm and 20 mm, the radiant heat was 92.29 kW and 117.43 kW each. When the container was 1.0 m, it was 364.35 kW and 405.88 kW each.

• International Journal of Automotive Technology
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• v.7 no.1
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• pp.1-7
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• 2006

The ignition delay of a dual fuel system has been numerically investigated by adopting a constant volume chamber as a model problem simulating diesel engine relevant conditions. A detailed chemical kinetic mechanism, consisting of 28 species and 135 elementary reactions, of dimethyl ether (DME) with methane ($CH_{4}$) sub-mechanism has been used in conjunction with the multi-dimensional reactive flow KIVA-3V code to simulate the autoignition process. The start of ignition was defined as the moment when the maximum temperature in the combustion vessel reached to 1900 K with which a best agreement with existing experiment was achieved. Ignition delays of liquid DME injected into air at various high pressures and temperatures compared well with the existing experimental results in a combustion bomb. When a small quantity of liquid DME was injected into premixtures of $CH_{4}$/air, the ignition delay times of the dual fuel system are longer than that observed with DME only, especially at higher initial temperatures. The variation in the ignition delay between DME only and dual fuel case tend to be constant for lower initial temperatures. It was also found that the predicted values of the ignition delay in dual fuel operation are dependent on the concentration of the gaseous $CH_{4}$ in the chamber charge and less dependent on the injected mass of DME. Temperature and equivalence ratio contours of the combustion process showed that the ignition commonly starts in the boundary at which near stoichiometric mixtures could exists. Parametric studies are also conducted to show the effect of additive such as hydrogen peroxide in the ignition delay. Apart from accurate predictions of ignition delay, the coupling between multi-dimensional flow and multi-step chemistry is essential to reveal detailed features of the ignition process.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.25-36
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• 1998

Explosion and fires can occur in all segments of chemical and petroleum industries because of complexity of process, usage and storage of flammable and reactive chemicals, and operating conditions of high pressure and temperatures. Especially chemical plants have high possibility of the occurrence of BLEVE(Boiling Liquid Expanding Vapor Explosion)and Fireball. In this study, a computer program was developed for the effect assessment of BLEVE and Fireball. BLEVE was analysed by three explosion models of physical explosion model, isothermal expansion model and adiabatic expansion model and Fireball using solid model. The parametric sensitivity analysis has been done for the models of BLEVE and Fireball. The damage by BLEVE and Fireball of Benzene and Toluene and m-Xylene were estimated.

• Journal of Korean Society of Disaster and Security
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• v.10 no.2
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• pp.29-34
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• 2017

LPG is a substance that requires a lot of attention because it can cause fatal damage to people and environment when an accident occurs. LPG is frequently accidents in transportation facilities as well as fixed facilities, among which LPG tank lorries are the most frequent accidents. When the LPG tank is evacuated, the LP gas leaks into two phases, leaks mostly to the gas and leaks to some liquid. At this time, the leaked gas will also sink downward because it is heavier than air, and if it continues to leak, it may form an explosion and explode by the ignition source. The purpose of this study is to present the evacuation distance by analyzing the effect distance of the LPG liquefied petroleum gas in the event of explosion. As a result of calculation of the scattering radius of the fragment, the cylinder fragment was scattered up to 561 m. Therefore, it is appropriate to set the distance to be escaped when the LPG tanker leaks to 561m or more.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.865-875
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• 2018

Selection of optimum reaction conditions during deoxygenation process of palm oil is essential factor to obtain the maximum yield of bio-jet fuel. In this context, the deoxygenation of palm oil was carried out in a fixed bed reactor with an internal diameter of 1 inch loaded with a 1 wt.% $Pt/Al_2O_3$ catalyst. The composition of the organic liquid product(OLP), which can be utilized as a transportation fuel through the upgrading process, was analyzed by a gas chromatography method. The palm oil/hydrogen ratio and hydrogen pressure in the feed affected the decarboxylation(DCB) and hydrodeoxygenation(HDO) reactions, resulting in a change in the composition of the OLP. As the reaction temperature increased, the continuous cracking reaction of the deoxygenation product was promoted and the product composition in the $C_5{\sim}C_{14}$ region was increased. Thus, the results can help to understand the characteristics of deoxidation reaction of palm oil as well as the subsequent process, hydro-upgrading, to obtain the maximum yield of bio-jet fuel.