• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.238-247
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• 2023

Liquefied petroleum gas (LPG) is an attractive fuel for ships considering its current technology and economic viability. However, safety guidelines for LPG-fueled ships are still under development, and there have been no cases of applying LPG propulsion systems to small and medium-sized ships in Korea. The purpose of this study was to perform an objective risk assessment for the first marine LPG engine system and propose safe operational standards. First, hazard and operability (HAZOP) analysis was used to divide the engine system into five nodes, and 58 hazards were identified. To compensate for the subjectivity of qualitative evaluation using HAZOP analysis, fuzzy set theory was used, and additional risk factors, such as detectability and sensitivity, were included to compare the relative weights of the risk factors using a fuzzy analytical hierarchy process. As a result, among the five risk factors, those with a major impact on risk were determined to be the frequency and severity. Finally, the fuzzy technique for order of preference by similarity to ideal solution (TOPSIS) was applied to select the risk rank more precisely by considering the weights of the risk factors. The risk level was divided into 47 groups, and the major hazard during the operation of the engine system was found through the analysis to be gas leakage during maintenance of the LPG supply line. The technique proposed can be applied to various facilities, such as LPG supply systems, and can be utilized as a standard procedure for risk assessment in developing safety standards for LPG-powered ships.

• Journal of the Korean Geophysical Society
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• v.5 no.2
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• pp.75-86
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• 2002

A TSP(Tunnel Seismic Prediction) survey which is modified VSP(Vertical Seismic Profiling) survey applied in tunnel was carried out at Pyongtaek and Incheon liquefied petroleum gas(LPG) storage cavern during excavation. The TSP survey in Pyongtaek LPG storage cavern which is located below Namyangho was performed to confirm the location and orientation of the fault detected at pre-investigation stage. The TSP survey was carried out in access tunnel, construction tunnel, and watercurtain tunnel to characterize 3 dimensional figure of the fault. The results of TSP survey are compared four in vestigation boreholes drilled in shelter of access tunnel. The fault was also detected by borehole survey and the location was coincided with the result of TSP survey. Depending on the result of TSP survey and core logging, the design such as cavern layout and length was changed. Another TSP survey was performed in Incheon LPG storage cavern which is located below sea. Because of poor geological information at pre-investigation stage and suffering from heavy leakage of groundwater, the TSP survey to detect fracture zone was carried out. The support and grouting design was reflected by the result of TSP survey.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.52-59
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• 2014

In general, sulfur containing odorants are added to fuel gases, such as LPG, and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. In this study, sulfur free odorant for low sulfur fuel and prevention of metal corrosion were developed to replace current sulfur containing odorant for gas fuel. They were selected from 12 odorant containing non-sulfur organic compounds and evaluated by odor olfactory method (odor quality, odor intensity). Finally, selected mixture odorants were methyl isovalerate, methyl acrylate, 2-ethyl-3-methyl pyrazine with blending ratio of 50% : 40% : 10%. Final Sulfur free odorant was added 40 wt ppm in LPG fuels and evaluated fuel quality characteristics, metal corrosion test and long term stability of LPG fuel. It were limit in current LPG fuel standard in fuel quality characteristics. Final Sulfur free odorant also had no influence on metal corrosion and long term stability test with 60 days by adding in LPG fuels. Finally, they were shown to be warning agent candidates to reduce sulfur content and metal corrosion for LPG fuel.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.87-94
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• 2003

Recently, LPLi(Liquied-Phase LPG injection) system is studied for the new stringent emission regulations. But , there are some problems to be solved such as injector tip icing and fuel leakage for LPLi system development. In this paper, the icing problem near injector tip which leads to difficulty of accurate A/F control was studied and reported. Icing of injector tip and port wall was observed at all the cases in this study regardless of injection duration and angle, air humidity change. The spray angle of LPLi was observed approximately two times wider than that of Gasoline injection. This makes the LPLi spray collide with intake port around injector tip. Temperature of the wetted area was decreased and icing of water vapor contained in intake air because of evaporation of the fuel film. The ice of the injector tip and port wall is also affected by the materials related to heat transfer.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.59-62
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• 2000

Almost accidents related with gas have started with the leakage of LPG(Liquefied Petroleum Gas) in the open air. But experimental data of LPG leak jet are difficult to find because the safety of experiment is hard to secure and its phenomenon is not steady but transitional. This study is focused on the phenomena of injection jet of liquid butane to the open air. Simple experiment shows that only liquid butane jet in the open air is possible due to the slow vaporization because of low temperature difference between the liquid and air and low vapor pressure of liquid butane. Comparing with the water, 25~40% more liquid butane flow through the tube under the same pressure difference driving.

• 한국가스학회:학술대회논문집
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• 2000.09a
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• pp.87-94
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• 2000

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.49-54
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• 2015

The purpose of this study is to assess the risk of depending on the presence or absence of safety device of domestic heating and drying furnaces, by derivation and analysis of accident frequency of safety devices through FTA (Fault Tree Analysis). Installation standards are lacking in Korean for the safety device of LPG heating and drying furnace, which have a risk of explosion due to structure to trap the leaked gas. Four different safety devices were selected on the basis of NFPA and national standards for combustors of other equipment. Effects of frequency reduction in accidents were analyzed before and after installing the safety devices respectively. As a result, a minimal leakage safety device was presented for preventing damages from gas leak of domestic LPG heating and drying furnace.

• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.60-63
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• 2018

This paper presents the FEM analysis results on the strength safety of a gas valve for a LPG cylinder. Based on the FEM analysis, the maximum von Mises stress on the boundary zone between a safety valve and the upper area of the thread is 99.2 MPa for the supplied gas pressure of 3.5 MPa in which the gas valve is fully opened. The maximum von Mises stress of 99.2 MPa is considered as safety value, because that value is lower than the yield stress of a brass material. In this case, the maximum deformation at the upper right part of the pressure regulator is 0.002mm. The maximum deformation zone is not a meaning part of the sealing part such as an O-ring or a diaphragm of a gas valve and a pressure regulator. The proposed hybrid gas valve model in which is integrated with a conventional cut-off valve and a pressure regulator is recommended as a gas leakage free mechanism and minimized compact size for a LPG cylinder.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.36-40
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• 2009

In this study, we surveyed 544 drivers, who had taken the education course for autogas car drivers, to figure out their safety awareness status including the recognition of hazards of gas leaking from autogas cars and response attitude toward them. As a result of the survey, we found out that 63% of the responders recognized the hazards of gas leakage and 79% preferred parking in the aboveground areas. For the necessity of introducing restrictions on autogas cars parking in underground lots, 58% of all responders answered yes while 71% of the responders aged over fifties and 73% of them who responded to have known the hazards of parking in underground answered in the affirmative. Furthermore, we found out that responders who had recognized the hazards preferred aboveground parking areas, and the responders who had preferred the aboveground recognized the hazards of parking autogas cars underground and felt the necessity of restricting them from parking in underground relatively high. Through the analysis of these results, we can analyse that the drivers who are aware of the hazards of gas leakage have higher safety attitude for hazards than the other drivers who are not aware of them.

• Journal of the Korean Institute of Gas
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• v.17 no.3
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• pp.8-13
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• 2013

The purpose of this paper is to study for fire example by fuel leakage in LPG Vehicle. At first example, the car was repaired the fuel line that was connected with pressure hose between fuel regulator and injector in engine. But the service man was not very tighten with regular torque. At a result, the gas leaked on hot parts of engine. It verified the production of fire by engine heat. At second example, when the repair man, after replacement the injector, inserted the injector in a assembling part of it, he didn't the transform condition of fixing part. Therefore, the tearing phenomenon of O ring producted the controlled leakage of fuel by the injector deflection. It found the fact that the fuel leaked with gap of O ring. At third example. the fuel-cut solenoid valve was lined with pressure regulator unit. But the service man didn't throughly certify the leaked work of connected parts after repaired it. As a result, it certified the fire by engine heating leaked liquefied petroleum gas. Therefore it have to minimize the fire production that the driver should do no problem to throughly manage the fuel system.