• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.41-48
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• 2020

This study performed a quantitative risk assessment for hydrogen-CNG complex refueling stations. Individual and societal risks were calculated by deriving accident scenarios that could occur at hydrogen and CNG refueling stations and by considering the frequency of accidents occurring for each scenario. As a result of the risk assessment, societal risk levels were within the acceptable range. However, individual risk has occurred outside the allowable range in some areas. To identify and manage risk components, high risk components were discovered through risk contribution analysis. High risks at the hydrogen-CNG complex refueling station were large leakage from CNG storage containers, compressors, and control panels. The sum of these risks contributed to approximately 88% of the overall risk of the fueling station. Therefore, periodic and intensive safety management should be performed for these high-risk elements.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.36-44
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• 2001

In case of low odor level, accident probabilities are very high Otherwise, when the odorant concentration is too high, the deterioration of pipeline and governor facilities and the environmental problems may occur. Odorants fade in the pipeline and other equipment due to physical and chemical adsorption and reactions with odorant and materials. So, it is very important to maintain odorant concentration properly In this study, the current status of odorization technologies has been reviewed. And the characteristics of small odorant system have been analyzed. In case that the small odorant system Is introduced in our country, this paper is proposed the feasible management plan and showed feasibility results through the analysis of current available technology.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.43-48
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• 2021

This study was conducted using FLACS, a specialized gas accident analysis program. Hydrogen refueling stations subject of safety analysis, consist of compression facilities, storage tanks, and hydrogen piping. The safety analysis of potential risk factors was conducted after reflecting the design specifications of major facilities and components, environmental conditions around hydrogen refueling stations, etc. As of 2021, about 70 refueling stations in Korea are available, and 1,200 are scheduled to be introduced in the next 2040. To prepare for possible accidents caused by potential hazards for the safe distribution of hydrogen refueling stations, we intend to derive hydrogen leakage diffusion scenarios and review their safety.

• Fire Science and Engineering
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• v.17 no.1
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• pp.8-20
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• 2003

Natural gas has been supplied through underground pipelines and valve stations as a new city gas in Seoul. In contrast to its handiness the natural gas has very substantial hazards due to fires and explosions occurring from careless treatments or malfunctions of the transporting system. The main objectives of this study are to identify major hazards and to perform risk assessments after assessing reliabilities of the composing units in dealing with typical pipeline networks. there-fore two method, fault tree analysis ;1nd event tree analysis, are used here. Random valve stations are selected and considered its situation in location. The value of small leakage, large rupture, and no supply of liquefied natural gas is estimated as that of top event. By this calculation the values of small leakage are 3.29 in I)C valve station, 1.41 in DS valve station, those of large rup-lure are $1.90Times10_{-2}$ in DC valve station, $2.32$\times$10^{-2}$ in DS valve station, and those of no supply of LNG to civil gas company are $2.33$\times$10 ^{-2}$ , $2.89$\times$10^{-2}$ in each valve station. And through minimal cut set we can find the parts that is important and should be more important in overall system. In DC valve station one line must be added between basic event 26,27 because the potential hazard of these parts is the highest value. If it is added the failure rate of no supply of LNG is reduced to one fourth. In DS valve station the failure rate of basic event 4 is 92eye of no supply of LNG. Therefore if the portion of this part is reduced (one line added) the total failure rate can be decreased to one tenth. This analytical study on the risk assessment is very useful to prepare emergency actions or procedures in case of gas accidents around underground pipeline networks and to establish a resolute gas safety management system for loss prevention in Seoul metropolitan area.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.387-392
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• 2010

This experiment was conducted to investigate the effect of fermented spent mushroom substrate (FSMS) on growth performance, blood profile, intestinal microflora and ammonia gas production of feces in broiler chickens. A total of three hundred sixty, 1-day-old male broiler chicks (Ross) were randomly divided into 3 groups with 6 replicates of 20 birds each. The treatments were control (free FSMS), 15% FSMS (basal diet with 15% FSMS) and 30% FSMS (basal diet with 30% FSMS). The final body weight and body weight gains were slightly improved in 30% FSMS than control (P<0.05). Feed intake and feed conversion were significantly improved as compared to those of the control groups. The Leukocytes of blood serum in FSMS groups were significantly decreased as compared to those of control groups. There are no significant differences among the groups in the contents of albumin (ALB), total cholesterol (TCHO), glucose (GLU), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in blood serum. The content of total glucose (TG) in 30% FSMS containing dietary groups was significantly decreased as compared to that of the control groups. The content of HDLC in 30% FSMS containing dietary groups was significantly increased as compared to that of the control group. The number of lactobacillus in the intestinal microflora were significantly increased in chicks fed FSMS groups. The ammonia gas production in FSMS groups was siginificantly decreased as compard to that the control groups. These results indicated that dietary FSMS exerted growth performance for feeding broiler.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.23-28
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• 2016

"Eco-friendly" automobile has been a symbol of the Low Carbon, Green Growth strategy that Korea government decided to pursue. In line with the recent policy trend, a number of new LPG stations are being constructed. However, communities where mass storage are installed have been suffered from risk of serious accidents. In this work, economic analyses for different installation methods has been performed to prevent accidents in LPG filling station. The review shows that the underground storage is beneficial for the maintenance and the effective land use.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.237-242
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• 2019

In the hydrogen refueling station (HRS), it is need the pre-cooling system (PCS) to limit the inside temperature ($85^{\circ}C$) of the onboard thank (700 bar) and to charge the hydrogen at short time (within 3 minutes) to fuel cell electric vehicle (FCEV). From those safety reasons, the temperature of hydrogen gas must be controled $-33^{\circ}C$ to $-40^{\circ}C$ in PCS. The cooling test of the gaseous ($N_2$, He, $H_2$) was carried out using heat exchanger (pre-cooler) by indirect cooling and direct cooling method. It was confirmed that the temperature of hydrogen gas had below $-40^{\circ}C$ at below $-75^{\circ}C$ of chiller temperature in direct cooling.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.13-18
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• 1998

• 한국가스학회:학술대회논문집
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• 1999.09a
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• pp.14-19
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• 1999

• Journal of Energy Engineering
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• v.23 no.4
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• pp.223-229
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• 2014

This study investigated the explosion characteristics of HCNG fuel using a simulation tool. The damage caused by the storage container explosion and vapor cloud explosion in a gas station was predicted. In case of an vapor cloud explosion in the HCNG station, 50~200kPa explosion pressure was predicted inside the station. When the cylinder explosion was occurred, in case of hydrogen, the measured influential distance of overpressure was 59m and radiant heat was 75m. In case of CNG, influential distance of overpressure was 89m and radiant heat was 144m would be estimated. In case of 30% HCNG that was blended with hydrogen and CNG, influential distance of overpressure was 81m and radiant heat was 130m were measured. The damage distance that explosive overpressure and radiant heat influenced CNG was seen as the highest. HCNG that was placed between CNG and hydrogen tended to be seen as more similar with CNG.