• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.76-85
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• 2023

Demand for hydrogen as a renewable energy resource is increasing. However, unlike conventional fossil fuels, hydrogen requires a dedicated refueling station for fuel supply. A risk assessment of hydrogen refueling stations must be undertaken to secure the infrastructure. Therefore, in this study, a risk assessment for hydrogen refueling stations was conducted through both qualitative and quantitative risk assessments. For the qualitative evaluation, the hydrogen dispenser module was evaluated as two nodes using the hazard and operability (HAZOP) analysis. The risk due to filter clogging and high-pressure accidents was evaluated to be high according to the criticality estimation matrix. For the quantitative risk assessment, the Hydrogen Korea Risk Assessment Module (Hy-KoRAM) was used to indicate the shape of the fire and the range of damage impact, and to evaluate the individual and social risks. The individual risk level was determined of to be as low as reasonably practicable (ALARP). Additional safety measures proposed include placing the hydrogen refueling station about 100m away from public facilities. The social risk level was derived as 1E-04/year, with a frequency of approximately 10 deaths, falling within the ALARP range. As a result of the qualitative and quantitative risk assessments, additional safety measures for the process and a safety improvement plan are proposed through the establishment of a restricted area near the hydrogen refueling station.

• Journal of Hydrogen and New Energy
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• v.23 no.6
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• pp.612-618
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• 2012

In this paper, in order to prevent electric shock of high voltage system of HFCV after crash test, insulation performance measurement methods were studied. Under conditions of in-use, insulation performance tests can be divided into measurement method using the vehicle's own RESS as DC voltage source and measurement method using DC voltage from off-vehicle sources. However, these tests can not be applied after a post-crash because parts of high voltage system cover should be removed, and insulation performance can be influenced during these tests. Therefore, we proposed post-crash insulation performance test methods for preventing electric shock through problem analysis of previous post-crash insulation performance tests. Also, test equipment which can measure voltage absence and total energy was developed. We verified performance of the equipment through experiments with vehicle test.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.1-6
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• 2012

This paper presents a stress safety of a composite pressure cylinder for a hydrogen gas vehicle. The composite pressure cylinder in which is composed of an aluminum liner and carbon fiber wound layers contains 104 liter hydrogen gas, and is compressed by a filling pressure of 70 MPa. The FEM computed results are analyzed based on the US DOT-CFFC basic requirement for a hydrogen gas cylinder and KS B ISO specification. The FEM results indicate that the stress, 255.2 MPa of an aluminum liner is sufficiently low compared with that of 272 MPa, which is 95% level of a yield stress for aluminum. Also, the composite layers in which are wound on the surface of an aluminum cylinder are safe because the stress ratios from 3.46 to 3.57 in hoop and helical directions are above 2.4 for a minimum safety level. The proposed composite pressure cylinder wound by carbon fibers is useful for 70 MPa hydrogen gas vehicles.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.1-9
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• 2020

In Korea, hydrogen stations are being promoted and commercialized. However, the risk assessment for the hydrogen station is not clear. In particular, it is not clear how to calculate the risk and acceptable criteria for a hydrogen station. Therefore, in this study, three hydrogen stations being installed were selected and general risks were calculated and the social risk of each hydrogen station was calculated. In general, the method of risk assessment is individual/social risk. This is an individual's death rate considering the frequency of accidents, And the likelihood of death according to the number of nearby residents. These can be used to calculate the level of risk for a hydrogen station. However, this method of calculate risks is the criteria for judging whether it is acceptable are unclear. For this reason, this study investigated the allowable standards for foreign risks and considered that they were acceptable by applying the risks of selected domestic hydrogen stations.

• Journal of the Korea Computer Graphics Society
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• v.15 no.2
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• pp.35-40
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• 2009

In this paper, we present the web3D-based virtual reality(VR) system for the safety education of the hydrogen station. Currently, hydrogen is considered the next generation energy, and hydrogen station is a part of core infrastructure in hydrogen industry. However, the experience of safety equipment in the hydrogen station is limited to the non-experts, because it is a restricted area in general industry. Therefore, using the event driven method, we develop the VR system to transfer the information of hydrogen station to the non-experts. Using our system, user experiences the safety concerns in the hydrogen station, and also learn the informations of hydrogen energy.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.33-38
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• 2019

In order to invigoration the hydrogen economy, production of hydrogen needed for hydrogen charging stations and hydrogen fuel cells is needed. Generally, it is reforming used to coal fuel or natural gas. Other technologies include water electrolysis using pure water. Among these water electrolysis technologies, development is mainly carried out using PEM(Polymer Electrolyte Membrane electrolysis). In this study, the company aims to identify potential harmful hazards to PEM electrolysis hydrogen stations in the development stage among hydrogen charging stations. In order to find the hazardous factors in the facilities of the electrolysis and hydrogen charging stations, we were analyzed by Failure Mode & Effect Analysis(FMEA).

• Journal of the Korean Society of Safety
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• v.6 no.2
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• pp.31-36
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• 1991

Quenching effects of acetylene and hydrogen into oxygen detonation by using detonation arrester ［DA］are studied in this paper. The experiments were carried out in cylinderical shock tube. 5m long, 30mm dia., with stolchlometric ratio ［SR］of each gas and 10-l20$\mu$ Cell Size of brass and Stainless Steel of DAs were installed in it To clarify arresting ability correlation with initial pressure, Pi, critical thickness, Tct, and shapes of supporting panel of DA are also investigated It is found that ­detonation velocities has most dependency on Pi, it shows notable changes around 0.5kgf/$\textrm{cm}^2$ for hydrogen, 0.15kgf/$\textrm{cm}^2$ for acetylen respectively, ­DA can be safety device able to arrest shock wave of detonation, ­over Tct flame transmission might be only the factor has to be considered, ­acetylene seems to be much more stronger detonation characteristics than hydrogen because of reaction heat.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.29-34
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• 2013

When flammable gases are mixed with air or oxygen in the explosion concentration range and are ignited by sufficiently large electrostatic discharge energy, they may explode causing severe disaster in workplace. The minimum ignition energy(MIE) of single gas-air mixtures has been already investigated by many research, but the MIE of mixtures of more than ternary gas mixture is not examined yet. The purpose of this study is to investigate the MIE of a ternary gas(methane, ethylene, hydrogen, propane) mixtures experimentally. The results of our experiment show that the ignition of a methane-ethylene-air, methane-hydrogen-air, methane-propane-air, ethylene-hydrogen-air, ethylene-propane-air and hydrogen-propane-air mixture due to electrostatic discharge energy primarily depends on that the mixture: the MIE decreases gradually with the increase of having the lower MIE than other mixture ratio in the normal atmospheric pressure.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.158-165
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• 2022

Eco-friendly policies proposed by the government of The Republic of Korea have encouraged the use of eco-friendly vehicles. Hydrogen vehicles have exhibited the highest growth rate, although the current number of registered vehicles is low. In hydrogen vehicles, a thermally activated pressure relief device (TPRD) is installed to prevent explosions in the hydrogen gas cylinder. When discharged due to low ignition energy, hydrogen gas readily forms a jet flame. The risks induced by such jet flames were analyzed through a numerical analysis. Jet flames can activate TPRDs installed in nearby hydrogen gas cylinders. As a result, high-voltage cables exposed in the lower area of a vehicle can ignite within seconds. There was a 9.5-kW/m2 area around the vehicle (which can result in casualties) at a distance of ~5 m from the hydrogen gas cylinder, and a 37.5-kW/m2 area (which can cause significant damage) in the form of an inverted triangle toward the lower section of the vehicle. We believe that the risk factors analyzed herein should be considered for addressing accidents in hydrogen vehicles.

• Journal of Hydrogen and New Energy
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• v.23 no.3
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• pp.219-226
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• 2012

A nuclear fusion fuel cycle plant is composed of various subsystems such as a hydrogen isotope storage and delivery system, a tokamak exhaust processing system, and a hydrogen isotope separation system. Korea shares in the construction of the International Thermonuclear Experimental Reactor fuel cycle plant with the EU, Japan and US, and is responsible for the development and supply of the storage and delivery system. We thus present details on the hydrogen isotope process safety. The main safety analysis procedure is to use a hazard and operability study. Nine segments were studied how the plant might deviate from its design purpose. We present a detailed description of the process, examine every part of it to determine how deviations from the design intent can occur and decide whether these deviations can give rise to hazards. We determine possible causes and note protective systems, evaluate the consequences of the deviation, and recommend actions to achieve our safety goal.