• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.365-369
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• 2013

With the wide application of ASP (alkaline-surfactant-polymer) flooding, the scaling becomes more and more serious, which is harmful to the oilfield and environment. In order to investigate the effects of HPAM on calcium carbonate crystallization, the crystallization behaviors of $CaCO_3$ in HPAM (Hydrolyzed polyacrylamide) solutions were studied and the composition and morphology of $CaCO_3$ crystal were investigated in different concentrations of polyacrylamide solutions. The crystal forms and morphologies of $CaCO_3$ were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that the crystallization of $CaCO_3$ is strongly influenced by the HPAM. The paper analyzed the internal cause, and the results show: The reasons leading to the change of morphology are carboxyl groups in polyacrylamide molecule and $Ca^{2+}$ in solution form chelates by coordination bond. And the chelates are adsorbed on the calcium hydroxide surfaces of solid-liquid interfaces so as to change the formation rate of calcium carbonate crystal nucleus. The research provides a reliable basis for the mechanism research of the scaling problem in the oil extraction process of ASP flooding and the adoption of scale inhibition and scale inhibitor.

• Journal of the Korean Society of Combustion
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• v.4 no.2
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• pp.43-50
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• 1999

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburetion system was first introduced, then the system has been changed to a precisely controlled gas injection system, but this gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power. This study addresses the analysis of the LPG spray from diesel injectors. The spray images are visualized and compared with diesel sprays in a wide injection pressure range. The photographs show much wider dispersion of LPG sprays.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.21-26
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• 1999

Liquefied petroleum gas(LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburation system was firstly introduced, then the system changed into a gas injection system controlled precisely, but those gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power. This study addresses the analysis of the LPG spray from diesel injectors. The spray images are visualized and compared with diesel sprays in a wide injection pressure range. The photographs show much wider dispersion of LPG sprays.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1075-1080
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• 2004

In this study, performance and emissions characteristics of an liquefied petroleum gas (LPG) engine converted from a diesel engine were examined by using mixer system and liquid propane injection (LPi) system fuel supply methods. A compression ratio for the base diesel engine, 21, was modified into 8, 8.5, 9 and 9.5. The cylinder head and the piston crown were modified to roe the LPG in the engine. Ignition timing was controlled to be at minimum spark advance for best torque (MBT) each case. Engine performance and emissions characteristics are analyzed by investigating engine power, brake mean effective pressure (BMEP), brake specific fuel consumption (BSFC), volumetric efficiency, CO, THC and NOx. Experimental results showed that the LPi system generates higher power and lower emissions than the conventional mixer fuel supply method.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.1-7
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• 2009

In recent years, the needs for more fuel-efficient and lower-emission vehicles have driven to use the alternative fuel of LPG(Liquefied Petroleum Gas) which is able to meet the more stringent legislations without many modifications to current engine. LPLi (Liquid Phase LPG Injection) system (the 3rd generation LPG injection system) is the core technology to produce power equivalent to a gasoline engine with less emissions. The LPG fuel pump can supply the compressed LP gas in the liquid phase to engine. The fuel filter is attached in the fuel pump to eliminate the remnants in the liquid phased LP gas and the performance of blowoff flow for a pump can be varied with various filters. In this study, experiments were conducted to investigate the performance and efficiency of the impeller type LPG fuel pump under various filter types of microfiber, double mesh and external filter. And blowoff flow for a LPG fuel pump was measured according to the temperature of the fuel.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.279-287
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• 2009

Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of $C_{5+}$ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.28-35
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• 2005

Fuel injection rate of an injector is affected by various injection conditions such as injection duration, fuel temperature, injection pressure, and voltage in LPG liquid injection systems for either a port-fuel-injection(PFI) or a direct injection(DI) in a cylinder. Even fuel injection conditions are changed, the air-fuel ratio should be accurately controlled to educe exhaust emissions. In this study, correction factor for the fuel injection rate of an injector is derived from the density ratio and the pressure difference ratio. A voltage correction factor is researched from injection test results on an LPG liquid injection engine. A compensation method of the fuel injection rate is proposed for a fuel injection control system. The experimental results for the LPG liquid injection system in a SI-engine show that this system works well on experimental range of engine speed and load conditions. And the fuel injection rate is accurately controlled by the proposed compensation method.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.90-97
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• 2002

The interaction between airflow and liquid phase LfG (Liquefied Petroleum Gas) sprays was investigated in a steady flow system embodied in a wind tunnel to simulate the variety of flow inside intake port of LPG engines with liquid injection system. The spray developments in flowing fields with the mean velocities of 5.4, 21.5 and 42.4m/s were identified by spray visualization techniques such as Mie scattering and shadowgraph. The microscopic visualization using a telescopic lens system was performed to investigate the shape and size of liquid droplets in the spray. PDA measurement was used to get 1-dimensional velocity and diameter of liquid droplets. The fast co-flows make the spray field be compact and be lead upward to the injection direction. SMD of the spray was smaller at the fast flowing field. Spray width got bigger and SMD of the spray was smaller with higher injection pressure.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.128-132
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• 1963

A study has been made on the applicability of gas-liquid partition chromatography to the qualitative and quantitative analysis of complex mixture of gaseous hydrocarbons. While phthalate columns are widely used for this $purpose^9$, they separates neither saturated hydrocarbons from the unsaturated nor n-butane from isobutene or butene-1, therefore combined columns such as phthalate and dimethylsulfolane have been used for the perfect separation of gaseous hydrocarbons. It is shown by this study, however, that hydrocarbons having $C_1$ through $C_4$ can be separated with a 2-meters tetraethyleneglycol dimethylether column except ethane from ethylene, and trans-from cis-2-butene especially operated at $15^{\circ}C$$ using helium as the carrier gas. The column effluents were in order of methane, (ethane, ethylene), propane, propylene, isobutane, n-butane, isobutylene, butene-1, (trans-& cis-2-butene, isopentane), (butadiene-1, 3, n-pentane). Two kinds of liquified petroleum gases in market are analysed qualitatively and quantitatively. The results indicate that use of this 2-meters TEGDE column permits the separation and identification of all the commonly encountered aliphatic gaseous hydrocarbons.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.155-163
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• 2014

At gas stations, liquid fuels expand and contract in volume owing to temperature variations. In Korea, the ambient temperature varies between $-15^{\circ}C$ in winter and $35^{\circ}C$ in summer. The volume expansion coefficients of liquid fuels are about $0.1%/^{\circ}C$. To investigate this issue, we measured daily changes in fuel temperature and the delivered fuel temperature at gas stations. In addition, we scrutinized the daily, monthly, and annual changes in temperature over past 50 years in Korea. The results show that the temperature of the fuel in the storage tank was maintained at a stable value(summer or winter). Many factors, such as the surrounding conditions, fuel filling frequency, and gas station location, influence the delivered fuel temperature. The results of this study can be applied for establishing a national regulation and will contribute to fair transactions.