Guidelines for Vapor Cloud Explosion, Pressure Vessel Burst, BLEVE, and Flash Fire Hazards

Introduction: Assessment of the consequences of hazards such as fire and explosion is one of the most urgent and important steps to improve the level of safety in the current stations and those that are in the design process. The purpose of this study was to review the model of CNG Compressed Natural Gas releases and the range of damages to individuals and equipment. Moreover, we examined the observance of safe distance of this station to its surroundings. Materials and Methods: In this study, modeling the effects of fire and explosion on the CNG fuel station in Isfahan province was performed using ALOHA software. In this model, six scenarios were designed to create a hole with a diameter of 0.03m and a gap of 0.2m and width of 0.2 m in a pressure vessel. Results: It was observed that the toxic atmosphere was within the distance of 55 meters at a concentration of 65000 ppm. In the case of a gap, the toxic vapor cloud range could increase to 66 meters. The flammable superpower range was 89meters for the hole but 107 meters for the gap. The thermal radiation from the jet fire to the distance of 25meters was 10 kw/sqm for the hole, but the thermal radiation was 10 kw/sqm for the gap to 35meters. Conclusion: The most dangerous scenario was the Jet Fire, which involved not only the CNG station, but also the municipal parking area. Furthermore, the thermal radiation produced by the gap was greater than the hole with regard to the involved range.

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Study on Quantitative Risk Assessment of LGP Transportation in Road Tunnel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.4105 ◽

2011 ◽

Vol 255-260 ◽

pp. 4105-4109

Author(s):

Yu Chun Zhang ◽

Chuan He ◽

Yong Fang ◽

Xiao Qin Sun

Keyword(s):

Risk Assessment ◽

Quantitative Risk Assessment ◽

Liquefied Petroleum Gas ◽

Road Tunnel ◽

Boiling Liquid ◽

Flash Fire ◽

Vapor Cloud ◽

Property Loss ◽

Serious Injury ◽

The Impact

Based on the tunnel environment and the characteristic of flammability and explosion of liquefied petroleum gas (LGP), the leak of LPG tanker can induce heavy casualties and property loss in the tunnel. In order to study quantitative risk of LGP transportation in road tunnel, the data of 599 accidents and 659 accidental vehicles are collected. From these data, the proportion of LGP tanker accident in the total accident vehicles and million vehicles kilometer (MVK) tanker accident rates are obtained. By analyzing the leakage scene of LGP tanker, the possible accident types of the LGP transportation were analyzed, such as boiling liquid expanding vapor explosion (BLEVE), vapor cloud explosion (VCE), flash fire and jet fire, etc. The impact of leak time to various ranges of injury is studied in the condition of LGP continued leakage. The slight injury, serious injury and death radius of LGP leakage accidents are calculated in tanker loaded with different LGP quantity. In view of the accidental analysis, the countermeasures will be proposed to reduce the risk of LGP transportation in road tunnel.

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Note: Flash Fire Hazards in Fire Experiments

Journal of Fire Sciences ◽

10.1177/073490418300100507 ◽

1983 ◽

Vol 1 (5) ◽

pp. 396-398 ◽

Cited By ~ 1

Author(s):

Clayton Huggett

Keyword(s):

Fire Hazards ◽

Flash Fire ◽

In Fire ◽

Fire Experiments

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The Consequence Analysis of Pressure Vessel Failure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.66 ◽

2011 ◽

Vol 396-398 ◽

pp. 66-70

Author(s):

Zhi Xiang Xing ◽

Xian Jin Wang

Keyword(s):

Pressure Vessel ◽

Toxic Substance ◽

Gas Mixture ◽

Chemical Burns ◽

Software Simulation ◽

Consequence Analysis ◽

A Value ◽

Surrounding Environment ◽

Vapor Cloud ◽

Process Plants

After a chemical vessel suffering a rupture, BLEVE, fireball, jet fire, and dispersion of toxic substance may be the most common failure ways. Which give rise to a great threat to people’s life, process plants and surrounding environment. This paper presents an overview of the mechanism and the consequences for these failures; finally, ALOHA software simulation resorted to evaluating the consequences for all kinds of hazard, a vertical tank with the size of diameter=10, tank length=20m, containing the propane liquid/gas mixture with a volume of 1571 cubic meters, the mass of the chemical is calculated by the software automatically with a value of 554 tons. All the possible failures have been simulated by the ALOHA software, including：1) leaking tank, chemical is not burning as in escapes into the atmosphere; 2) leaking tank, chemical is burning as a jet fire; and 3) BLEVE, tank explodes and chemical burns in a fireball. Furthermore, there are three types hazard available to analyze the situation that chemical is not burning as it escapes into the atmosphere, they are: a) toxic area of vapor cloud; b) flammable area of vapor cloud; and c) blast area of vapor cloud explosion. The result reveals that the farthest threat zone reaches 2.2km in the case of a fireball triggered by a BLEVE, and the result has been viewed and discussed in details.

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An Overview of Vapor Cloud Explosions and Their Relationship to Equipment and Piping Configurations

Emerging Technologies in Fluids, Structures and Fluid Structure Interactions: Volume 1, Fluid Dynamics, Fluid Structure Interaction, and High Explosive Detonation ◽

10.1115/pvp2002-1473 ◽

2002 ◽

Author(s):

Adrian J. Pierorazio

Keyword(s):

Pressure Vessel ◽

Process Equipment ◽

Equipment Failure ◽

Construction Costs ◽

Free Expansion ◽

Vapor Cloud

Pressure vessel and piping layout is usually focused on minimizing construction costs and ensuring safety from an equipment failure standpoint. When the equipment contains flammable gases, a leak or rupture may result in a vapor cloud explosion (VCE). The severity of the resulting explosion is a function of the material reactivity, the equipment density, and the presence of structures that restrict the free expansion of the combusting cloud. This paper provides an overview of existing vapor cloud explosion prediction methodologies, with an emphasis on the effects of process equipment and piping spacing on the severity of a VCE.

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Explosions Caused by Corrosive Gases/Vapors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.844.65 ◽

2016 ◽

Vol 844 ◽

pp. 65-72 ◽

Cited By ~ 2

Author(s):

Jan Skřínský ◽

Ján Vereš ◽

Jana Trávníčková ◽

Andrea Dalecká

Keyword(s):

Mathematical Modeling ◽

Pure Hydrogen ◽

Explosion Pressure ◽

Maximum Explosion Pressure ◽

Vapor Cloud ◽

Property Loss ◽

And Storage ◽

Storage Facilities

Gas/vapor cloud explosions and fires are responsible for most of the largest property loss events worldwide in the hydrocarbon industry. Motivation for this article is to summarize explosion pressure caused by corrosive gases/vapors in terms of mathematical modeling. Presented explosions based on real scenarios of accidents associated with transport and storage facilities with corrosive flammable chemicals. While explosions of pure flammable chemicals are well described in the literature, the information about explosions of corrosive and toxic flammable substances is rather scarce. This work aims at studying the explosion behavior of pure hydrogen-air, pure ammonia-air, ammonia-hydrogen-air, ammonia-methanol-air, ammonia-ethanol-air mixtures at different initial temperatures and pressures. The results of mathematical modeling of the calculated maximum explosion pressure are described.

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Quantitative Fire Risk Assessment of Gas Pipeline Leakage

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.635-637.402 ◽

2014 ◽

Vol 635-637 ◽

pp. 402-406

Author(s):

Jing He ◽

Li Jing Zhang ◽

Gang Tao ◽

Xin Qi Dai

Keyword(s):

Risk Assessment ◽

Thermal Radiation ◽

Radiation Damage ◽

Fire Risk ◽

Gas Pipeline ◽

Damage Criterion ◽

Fire Model ◽

Fire Risk Assessment ◽

Flash Fire ◽

Vapor Cloud

Fire risk of gas pipeline leakage is high.The factors contributing to gas pipeline leakage most are third party damage, corrosion, design and incorrect operation. The accident consequences of gas pipeline leakage and quantitative risk assessment method of gas pipeline leakage consequence are analyzed. In order to achieve quantitative fire risk assessment of gas pipeline leakage, flash fire model, vapor cloud explosion model and thermal radiation damage criterion are analyzed. Firstly, the gas leakage quantity is estimated. Then, the heat radiation estimate flux, the thermal dose and damage range are got by using flash fire model, vapor cloud explosion model and the thermal radiation damage criterion respectively.Combined with an example of gas pipeline, damage ranges of different disaster patterns are estimated according to different gas pipeline leakage pattern. Through comparing the accident consequences of gas pipeline leakage, this paper provides some reliable scientific references for gas pipeline management departments.

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Technical textiles for protection against Arc-flash fire: Savesplash®

WEENTECH Proceedings in Energy ◽

10.32438/wpe.0602100 ◽

2020 ◽

pp. 67-78

Author(s):

Nandan Kumar ◽

Sainath Shrikant Pawaskar

Keyword(s):

Attenuation Factor ◽

Threshold Energy ◽

Single Layer ◽

Weather Conditions ◽

Electric Arc ◽

Risk Category ◽

Technical Textiles ◽

Flash Fire ◽

Level 3 ◽

Arc Flash

Flash fire caused by electric arc is different than that caused by flammable liquids/fumes or combustible dusts. A suitable protective clothing for protection against electric arc-flash must be designed as per Indian weather conditions. Currently available garments are manufactured using two or three layers of woven/nonwoven combinations to achieve higher Hazard Risk Category (HRC) rating (level 3 and above). However, they are heavy and not comfortable to the end users. Savesplash® is a single layer inherent flame-retardant knitted fabric. Its arc rating was determined using ASTM standards. It achieved arc thermal performance value (ATPV) of 41 cal/cm2, breakopen threshold energy (E_BT) of 42 cal/cm2 and heat attenuation factor (HAF) of 94% when tested as per ASTM F1959/F1959M-14 which translated into an arc rating of 41 cal/cm2. This is equivalent to HRC level 4 ratings as per National Fire Protection Association’s NFPA 70E standard (USA). Further, cut and sewn gloves (HM-100) developed using Savesplash® fabric reinforced with leather on palm area achieved ATPV of 63 cal/cm2 and HAF of 94.5% when tested as per ASTM F2675/F2675M-13.

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