Explosion Effects of LPG-Air Mixture in Congested Areas (original) (raw)
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Do tree belts increase risk of explosion for LPG spheres?
Journal of Loss Prevention in the Process Industries, 2004
In this work we used the Multi-Energy method to estimate the overpressure and the positive phase duration as a function of the distance from the explosion center, resulting from Vapor Cloud Explosions of LPG-air mixtures in highly congested areas near an LPG storage park. Simulations were made for square shaped zones planted with 10 m high trees and areas ranging from 50,000 m 2 to 250,000 m 2 . The criterion used to evaluate the risk to a LPG storage sphere was the stress failure of the diagonal arm braces supporting it. The explosion effects were studied for a 14.5 m diameter LPG storage sphere, located at distances ranging from 10 m to 100 m away from the border of the congested area. It is shown that congested areas of at least 100,000 m 2 can pose a risk to the LPG spheres with minimal filling. It is possible to conclude that it is better to keep a smaller number of full filled spheres than many spheres with less filling of LPG. We estimated for congested areas with 25 % blockage ratio that the minimum safe distance, measured from the border of the tree grove to the sphere, varies from 10 m, for 100,000 m 2 areas, to 87.6 m, for 250,000 m 2 areas. The tree spacing influence represented by the blockage ratio was also analyzed, showing it affects the sphere minimum safe distance. Finally, recommendations are made regarding the minimum safe distance between the spheres and the congested area, which seems to have a maximum value, as well as other ways to lessen the risk represented by explosions, but further conclusions would require a different approach as the loading would be Dynamic instead of Impulsive for tree belts with areas bigger than 250,000 m 2 .
Modelling the Consequences of Explosion, Fire and Gas Leakage in Domestic Cylinders Containing LPG
Annals of Medical and Health Sciences Research, 2018
Background: One of the substances with a high potential of damaging that nowadays is used widely in industry and human environment is LPG gas cylinders. Aim: The purpose of this study is modeling the consequences of gas leakage in domestic cylinders containing LPG (Liquefied petroleum gas). Subjects and Methods: The factors affecting discharging and emissions of LPG gas in 26, 60, 78 and 107 liter cylinders were described. ALOHA software was used as one of the best software for modeling gas emissions from tank storage, and emergency response program was presented at the time of the gas leakage based on modeling results. Results: The results showed that in all 4 types of examined cylinder up to distance 11 meters around the tank of LPG gas, concentration of gas is 33000 ppm. This area is located in the AGEL-3 that there is the risk of death and threatens the lives of people. In case of full gas leakage from 60, 78 and 107 liters cylinders, respectively at the distance of 11, 12 and 1...
Explosion characteristics of LPG–air mixtures in closed vessels
Journal of Hazardous Materials, 2009
The experimental study of explosive combustion of LPG (liquefied petroleum gas)-air mixtures at ambient initial temperature was performed in two closed vessels with central ignition, at various total initial pressures within 0.3-1.3 bar and various fuel/air ratios, within the flammability limits. The transient pressure-time records were used to determine several explosion characteristics of LPG-air: the peak explosion pressure, the explosion time (the time necessary to reach the peak pressure), the maximum rate of pressure rise and the severity factor. All explosion parameters are strongly dependent on initial pressure of fuel-air mixture and on fuel/air ratio. The explosion characteristics of LPG-air mixtures are discussed in comparison with data referring to the main components of LPG: propane and butane, obtained in identical conditions. (D. Razus), venerab@icf.ro (V. Brinzea), maria mitu@icf.ro (M. Mitu), doan@gw-chimie.math.unibuc.ro (D. Oancea).
Experimental evaluation of LPG tank explosion hazards
Liquefied-pressure gases (LPG) are transported and stored in the liquid phase in closed tanks under sufficiently high pressure. In the case of an accident, an abrupt tank unsealing may release enormous quantity of evaporating gas and energy that has a destructive effect on the tank and its surroundings.
Journal of Hazardous Materials, 2007
The maximum rates of pressure rise of propylene-air explosions at various initial pressures and various fuel/oxygen ratios in three closed vessels (a spherical vessel with central ignition and two cylindrical vessels with central or with top ignition) are reported. It was found that in explosions of quiescent mixtures the maximum rates of pressure rise are linear functions on total initial pressure, at constant initial temperature and fuel/oxygen ratio. The slope and intercept of found correlations are greatly influenced by vessel's volume and shape and by the position of the ignition source -factors which determine the amount of heat losses from the burned gas in a closed vessel explosion. Similar data on propylene-air inert mixtures are discussed in comparison with those referring to propylene-air, revealing the influence of nature and amount of inert additive. The deflagration index K G of centrally ignited explosions was also calculated from maximum rates of pressure rise.
Evaluating the potential for overpressures from the ignition of an LNG vapor cloud during offloading
Journal of Loss Prevention in the Process Industries, 2011
Ignition of natural gas (composed primarily of methane) is generally not considered to pose explosion hazards when in unconfined and low-or medium-congested areas, as most of the areas within LNG regasification facilities can typically be classified. However, as the degrees of confinement and/or congestion increase, the potential exists for the ignition of a methane cloud to result in damaging overpressures (as demonstrated by the recurring residential explosions due to natural gas leaks). Therefore, it is prudent to examine a proposed facility's design to identify areas where vapor cloud explosions (VCEs) may cause damage, particularly if the damage may extend off site. An area of potential interest for VCEs is the dock, while an LNG carrier is being offloaded: the vessel hull provides one degree of confinement and the shoreline may provide another; some degree of congestion is provided by the dock and associated equipment. In this paper, the computational fluid dynamics (CFD) software FLACS is used to evaluate the consequences of the ignition of a flammable vapor cloud from an LNG spill during the LNG carrier offloading process. The simulations will demonstrate different approaches that can be taken to evaluate a vapor cloud explosion scenario in a partially confined and partially congested geometry.
Post-Accident Analysis of Vapour Cloud Explosions in Fuel Storage Areas
Process Safety and Environmental Protection, 1999
A Vapour cloud explosion which occurred in a large fuel storage area close to the harbour of Naples (Italy) was analysed by different methods. Useful 'experimental data' were obtained by the post-accident damage analysis (minimum overpressure experienced by different items) and by the seismograms recorded at different stations at the time of explosion (explosion duration and intensity).
QUANTITATIVE RISK ASSESSMENT IN LPG STORAGE AREA FOR DIFFERENT FIRE SCENARIOS
IAEME, 2019
The Risk Assessment is an important legal requirement which should be carried out in industries in order to prevent any incident in future and manage emergencies better. In this article a typical LPG (Liquefied Petroleum Gas) storage bullet of capacity 14.7m 3 and truck tanker of capacity 18 m 3 were selected for the study. Risk assessment was carried out for various fire scenarios such as BLEVE, VCE, and Jet fire which can happen in LPG storage area. The inputs used in the estimation are collected from various articles and from a typical LPG handling and storing industry in the southern part of Tamil Nadu. The meteorological conditions for the assumed Madurai region are given as an input data in the ALOHA software for dispersion predictions of various scenarios. The accident situations are selected from various reports and literatures of LPG storages around the world. By using the ALOHA software, the dispersion models are used to estimate dispersion concentrations, Blast effects, Flammable effects, Thermal radiation and Toxic effects. The results are arrived from the predicted and user defined inputs in ALOHA software with the references and industrial investigations.
Accidental release of toxic / flammable hazardous chemicals from chemical storage plants can cause serious injuries / property damage, situation becomes grievous, if the plant is situated in a densely populated area. During sudden release of a hazardous chemical from a storage tank the chemical stored inside the tank will vaporize and disperse in the atmosphere depending on the process and meteorological conditions at the time of release. The area that would be affected can be approximately calculated using fundamental principles of fluid dynamics through dispersion models. However the heavy gas dispersion calculations are very complicated and the results obtained are not truly representative of the actual scenarios. Since Liquefied Petroleum Gas ( LPG) is most commonly used in industry and domestic areas ,since it is a heavy gas , prediction of consequences due to LPG release is not possible by calculations, therefore an effort is being made to predict the consequence at different ...
Study of Internal Pressure Impact on Sphere Tank Towards Vapour Cloud Explosion: Feyzin Incident
International Journal on Advanced Science, Engineering and Information Technology
In the case of Liquefied Petroleum Gas (LPG) tank explosion(s), risk impact assessment on the storage facilities must be carried out. Since every LPG tank has its operating condition, it is essential to decide what the best operating conditions are for each tank. This effort is made to avert an accident from happening, as fires and explosions can be devastating in terms of lives lost and destruction to buildings and the environment. Boil-off and/or ignition of flammable gas can cause the pressure in the tank to increase. Therefore, a method called Planas-Cuchi is applied to determine the Peak Side-On Overpressure, P o , of the LPG tank during the occurrence of explosion. Thermodynamic properties of saturated propane, C 3 H 8 , has been chosen as a reference and basis of calculation to determine the parameters involved, such as Explosion Energy, E, Equivalent Mass of TNT, W TNT , and Scaled Overpressure, P S. A cylindrical LPG tank in Feyzin Refinery, France is selected as a point of study in this research. At the end of this study, the most suitable operating pressure of the LPG tank will be determined, and the results are compared and validated using the TNT Equivalent (BREEZE software), Baker-Strehlow model and ARIA investigation report.