• Explosives and Blasting
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• v.38 no.4
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• pp.1-15
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• 2020

With the increase of the utilization of underground space in Korea, explosion accidents at the underground facilities such as gas pipes have occurred frequently. In urban area with high population density, individual explosion accidents are likely to spread into large complex accidents. It is necessary to investigate the effect of explosion on the stability of underground structures in urban area. In this study, a sensitivity analysis was carried out to investigate the possible influence of nearby explosion on the stability of underground structure with 8 parameters including explosion conditions and rock properties. From the sensitivity analysis using AUTODYN, the main and interaction effects of each parameters could be determined. From the analysis, it was found that the distance between explosion point and tunnel, charge weight, and Young's modulus are the most important parameters on the stress components around a tunnel.

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.53-60
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• 2003

Accident occurred by gas explosion in house or building causes damage on lives and properties. To avoid secondary damage, this study drew area ratio of vent area with the experiment for pressure variation with vent area versus building volume by selection of model for different size and shapes of vent area generated by explosion. In addition, Appropriate model was chosen to predict the damage by minimum pressure with the experiment of opening are shapes. This model can prevent secondary damage with the selected vent area and shape to guarantee building safety.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.248-256
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• 2020

In this study, predictive models based on machine learning for evaluating the extent of hazardous zone of explosive gases are developed. They are able to provide important guidelines for installing the explosion proof apparatus. 1,200 research data sets including 12 combustible gases and their extents of hazardous zone are generated to train predictive models. The extent of hazardous zone is set to an output variable and 12 variables affecting an output are set as input variables. Multiple linear regression, principal component regression, and artificial neural network are employed to train predictive models. Mean absolute percentage errors of multiple linear regression, principal component regression, and artificial neural network are 44.2%, 49.3%, and 5.7% and root mean square errors are 1.389m, 1.602m, and 0.203 m respectively. Therefore, it can be concluded that the artificial neural network shows the best performance. This model can be easily used to evaluate the extent of hazardous zone for explosive gases.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.56-63
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• 2008

We have garnered 3,593 data of gas [Natural Gas (NG) and Liquefied Petroleum Gas (LPG)] accidents reported for 16 years from 1991, and then analyzed the accidents according to their types and causes based on the classified database. According to the results the gas leak has been the most common accident followed by the explosion and then fire accidents. The most frequent accident-occurring locations for fire, explosion and leak are recognized around the valve, hose and pipeline, respectively. In addition, we have applied the Poisson analysis to predict the most-likely probabilities of fire, explosion and release in the upcoming 5 years. From this research we have assured the successive database updating will highly improve the anticipating-probability accuracy and thus it will play a key role as a significant safety-securing guideline against the gas disasters.

• Journal of the Korean Institute of Gas
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• v.26 no.1
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• pp.27-33
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• 2022

As the scale of explosions diversifies along with the expansion of gas handling and storage facilities, studies on explosion-proof facilities in preparation for accidents is being actively conducted. The gastight door blocks the expansion pressure caused by blast waves or internal fires, and at the same time protects the personnel and equipment inside. For gastight doors, the regulations related to explosion-proof design are not clearly presented, and studies on the explosion pressure resistance performance evaluation of the facility are insufficient. In this study, the gastight door was modeled in a 3D shape with reference to the regulation ASTM regarding the gastight door standard. Afterwards, evaluation for blast-resistant performance of gastight door using Numerical simulation was evaluated by using ANSYS Explicit Dynamics to compare the deformation.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.7-11
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• 2007

There has been a report of fire and explosion accident in regenerated thermal oxidizer (RTO). This paper was to investigate accident causes of RTO in the resin re-treatment process. The experiments carried out physicochemical properties and thermal stability analyses by using flash point tester, flammable range apparatus, autoignition tester, GC/MSD and thermal screening unit. We inferred causes of fire and explosion from the regenerated thermal oxidizer to prevent an accident of its process.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.281-288
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• 2014

As a gas explosion is the most fatal accident in shipbuilding and offshore plant industries, all safety critical elements on the topside of offshore platforms should retain their integrity against blast pressure. Even though many efforts have been devoted to develop blast-resistant design methods in the offshore engineering field, there still remain several issues needed to be carefully investigated. From a procedure for calculation of explosion design pressure, impulse of a design pressure model having completely positive side only is determined by the absolute area of each obtained transient pressure response through the CFD analysis. The negative pressure phase in a general gas explosion, however, is often quite considerable unlike gaseous detonation or TNT explosion. The main objective of this study is to thoroughly examine the effect of the negative pressure phase on structural behavior. A blast wall for specific FPSO topside is selected to analyze structural response under the blast pressure. Because the blast wall is considered an essential structure for blast-resistant design. Pressure time history data were obtained by explosion simulations using FLACS, and the nonlinear transient finite element analyses were performed using LS-DYNA.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.12-19
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• 2015

$CO_2$ is non-flammable, non-toxic gas and not cause of chemical explosion. However, various impurities and some oxides can be included in the captured $CO_2$ inevitably. While the $CO_2$ gas was temporarily stored, the pressure in a storage tank would be reached above 100bar. Therefore, the tank could occur a physical explosion due to the corrosion of vessel or uncertainty. Evaluating the intensity of explosion can be calculated by the TNT equivalent method generally used. To describe the physical explosion, it is assumed that the capacity of a $CO_2$ temporary container is about 100 tons. In this work, physical explosion damage in a $CO_2$ storage tank is estimated by using the Hopkinson's scaling law and the injury effect of human body caused by the explosion is assessed by the probit model.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.46-64
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• 2019

Technical practice code, KGS GC101 2018, for explosion hazard area selection and distance calculation of gas facility was enacted and implemented from July 12, 2018. This code includes whole contents of IEC60079-10-1 2015 (Explosive atmospheres Part 10-1: Classification of areas - Explosive gas atmospheres), and clarifies the interpretation of ambiguous standards or adds guidelines for standards. KGS GC101 is a method for classifying explosion hazard place types: (1) Determination of leak grade (2) Determination of leakage hole size (3) Determination of leakage flow (4) Determination of dilution class (5) Determination of ventilation effectiveness, finally (6) Determination of danger place (7) Explosion The range of dangerous places can be estimated. In order to easily calculate this process, the program (KGS-HAC v1.14, C-2018-020632) composed by Visual Basic for Application (Excel) language was produced by Korea Gas Safety Corporation. We will discuss how to use codes and programs to select and set up explosion hazard zones for field users.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.197-205
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• 2015

Offshore structures for the gas production are exposed to the risk of gas leaks, and gas explosions can result in fatal damages to the primary structures as well as secondary structures. To minimize the damage from the critical accidents, the study of the dynamic response of structural members subjected to blast loads must be conducted. Furthermore, structural dynamic analysis has to be performed considering relationships between the natural frequency of structural members and time duration of the explosion loading because the explosion pressure tends to increase and dissipate within an extremely short time. In this paper, the numerical model based on time history data were proposed considering the negative phase pressure in which considerable negative phase pressures were observed in CFD analyses of gas explosions. The undamped single degree of freedom(SDOF) model was used to characterize the dynamic response under the blast loading. A blast wall of FPSO topside was considered as an essential structure in which the wall prevents explosion pressures from the process area to utility and working areas. From linear/nonlinear transient analyses using LS-DYNA, it was observed that dynamic responses of structures were influenced by significantly the negative time duration.