• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.41-44
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• 2021

In this paper, we propose a monitoring system that can monitor gas leakage concentrations in real time and forecast the amount of gas leaked after one minute. When gas leaks happen, they typically lead to accidents such as poisoning, explosion, and fire, so a monitoring system is needed to reduce such occurrences. Previous research has mainly been focused on analyzing explosion characteristics based on gas types, or on warning systems that sound an alarm when a gas leak occurs in industrial areas. However, there are no studies on creating systems that utilize specific gas explosion characteristic analysis or empirical urban gas data. This research establishes a deep learning model that predicts the gas explosion risk level over time, based on the gas data collected in real time. In order to determine the relative risk level of a gas leak, the gas risk level was divided into five levels based on the lower explosion limit. The monitoring platform displays the current risk level, the predicted risk level, and the amount of gas leaked. It is expected that the development of this system will become a starting point for a monitoring system that can be deployed in urban areas.

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.36-42
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• 2001

A leak of fuel gas in partially confined area creates a flammable atmosphere and give rise to an explosion, which is one of the most common accident in domestic. Observations from accident in domestic suggest that some explosions are caused by a quantify of fuel significantly less than lower explosion limit(LEL) amount required to fill the room, which is attributed to inhomogeneous mixing of leaked gas. The minimum amount of leaked gas for explosion is highly dependent on the mixing degree in the area. For lighter gas, such as methane, a high concentration tends to build up in the space from ceiling of room. But heavy gas, such as propane, a high concentration tends to build up in the space from bottom of room. This paper presents a method for analysing the explosion hazard in a room with very small amount of leaked gas. Based on explosion limit concentration, the gaussian distribution model is used to estimate the minimum amount of leak which yields a specified explosion pressure. The results demonstrate that catastrophic structural damage can be achieved with a volume of fuel gas which is less than 0.5 percent of the total enclosed volume in domestic. The method will help analyzing hazard to develop new safe device as well as investigating accident.

• Journal of the Korean Institute of Gas
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• v.26 no.5
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• pp.58-65
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• 2022

Gas explosion accidents could cause a catastrophe. we need specialized and systematic accident investigation techniques to shed light on the cause and prevent similar accidents. In this study, we had performed LPG explosion simulation using AUTODYN which is the commercial explosion program and predicted the damage characteristics of the structures by LNG explosive power. In the first step, we could get LPG's physical and chemical explosion properties by calculation using TNT equivalency method. And then, by applying TNT equivalency value about the explosion limit concentration of LPG on the 2D-AUTODYN simulation, we could get the explosion pressure wave profiles (explosion pressure, explosion velocity, etc.). In the last step, we performed LPG explosion simulation by applying to the explosion pressure wave profiles as the input data on the 3D-AUTODYN simulation. As a result, we had performed analyzing of the explosion characteristics of LPG in accordance with concentration through the 3D-AUTODYN simulation in terms of the explosion pressure behavior and structure destruction and damage behavior. The analyses showed that the generated stresses of the structures were lower than the compressive strengths in cases 1(two lane) and 2(four lane), while the generated stress in case 3(six lane) was 8.68e3 kPa, which exceeded the compressive strength of 5.89e3 kPa.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.2
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• pp.195-200
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• 2015

It is envisaged that the effect of increasingly stricter air emissions legislation implemented through IMO Annex VI and other local air quality controls, together with favorable financial conditions for the use of natural gas instead of liquid fuel oil as a bunker fuel, will see an increasing number of DF engine and single gas fuel engine applications to LNG carriers and other vessel types. As part of provision for the current international movements in the shipping industry to reduce GHG emission in air, new design concepts using natural gas as an alternative fuel source for propulsion of large commercial vessels, have been developed by shipyards and research institutes. In this study, an explosion analysis for a gas supply machinery room of LNG-fuelled container ship is presented. The gas fuel concept is employed for the high pressure ME-GI where a leakage in the natural gas double supply pipe to the engines is the subject of the present analysis. The consequences of a leak are simulated with computational fluid dynamics (CFD) tools to predict typical leak scenarios, gas cloud sizes and possible explosion pressures. In addition, capacity of the structure which is subject to explosion loads has been assessed.

• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.99-106
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• 2024

In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.383-390
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• 2022

Appropriate explosion proof electrical equipment should be installed in hazardous areas. In areas where hydrogen is handled, explosion proof electrical equipment adjacent to the hydrogen handing facility must be reviewed for selection of gas group IIC (or IIB+H₂) equipment. When selecting explosion proof electrical equipment for the flammable substance handling facility in areas where hydrogen and flammable substance are handled, the method to avoid gas group IIC (or IIB+H₂) equipment has been suggested by using the operating pressure of the hydrogen handling facility. When the operating pressure of the outdoor hydrogen handling facility is 1.065 MPa or less, it has been confirmed that there is no need to install gas group IIC (or IIB+H₂) equipment for the flammable substance handling facility adjacent to the hydrogen handling facility. And the method of selecting explosion proof electrical equipment for the flammable substance handling facility has been suggested as a flowchart, so it will be able to be utilized when selecting appropriate explosion proof electrical equipment.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.56-61
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• 2023

The plant is an important facility as a infrastructure, and ensuring safety against possible accidents such as gas leaks and explosions must be considered in the design. However, there is little study on explosion pressure in plants for reasons such as economic feasibility, and overpressure data on this field is insufficient. In this study, an experimental design plan considering the explosion scenario that may occur in the plant was presented, and the explosion pressure was confirmed through an explosion experiment. Hydrogen-methane mixed gas was used as a combustible material, and the effect of confinement and congestion on overpressure was studied. The effect of overlapping pressure waves during deflagration and the turbulence effect by congested pipes are discussed. The results of this study can be used as input data in various safety designs.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.44-59
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• 2020

This study analyzed a gas explosion accident. A gas smell from a underground coffee shop in the two-story building was reported to 119. A fire brigade was turned out, turned off the main valve of LPG gas cylinder on the roof, and checked the turning off of middle valve in the coffee shop. The fire brigade required a gas supplier and gas installer who arrived at the spot to take safety actions. Gas explosion occurred seven minutes after the fire brigade was withdrawn and two people died and 21 people were injured. A court decided that because the causes for gas explosion were not found, compensation responsibility could not be charged with the gas supplier, the gas installer, or Korea Gas Safety Corporation. In this reason, the court judged that only the fire brigade who was withdrawn without taking safety actions shall compensate victims or bereaved families. Therefore, fire brigades who turn out after a 119 report of a gas leak should take safety actions such as escaping people or preventing people's access and ventilating and be withdrawn when there is no possibility of fire or explosion.

• Journal of the Korean Institute of Gas
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• v.9 no.3 s.28
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• pp.9-14
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• 2005

To estimate the explosion characteristics of converted gas, the study was examined into effects of altering oxygen concentration and adding hydrogen. From the result of the experiment, as the concentration of converted gas and hydrogen were increased at $21\%$ oxygen concentration, the lower explosion limit was low. Minimum explosion oxygen concentration was $6\%$. Maximum explosion pressure of converted gas was $4.61 kg_f/cm^2$, now Maximum explosion pressure rising velocity was $130.75 kg_f/cm^2/s$ at converted gas concentration $40\%$. Also, minimum ignition energy was 0.13 mJ at converted gas concentration $50\%$.

• Proceedings of the Safety Management and Science Conference
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• 2010.04a
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• pp.81-95
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• 2010

Gas turbines generating power operate in high temperature condition and use natural gas as fuel. For that reason, there are many cases where damage is done to the hot gas parts caused by the high temperature and many accidents occur like gas explosions, then various efforts are needed to maintain the hot gas parts and prevent accidents. It is difficult to find the root causes of damage to the hot gas parts from the gas explosion caused by gas leakage through rotor cooling air line from fuel gas heat exchanger during the shut down. To prevent gas turbine from damage, removal of gas leakage inside of gas turbine is required by purging the turbine before firing, improving the fuel gas heating system and installing alarm systems for detecting gas leakage from stop valve to turbine while the gas turbine has shut down.