CFD Simulation and Mitigation with Boiling Liquid Expanding Vapor Explosion (BLEVE) Caused by Jet Fire (original) (raw)
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Journal of Loss Prevention in the Process Industries
Liquefied petroleum gas (LPG) is flammable and has risks of pool fires during its transportation, storage, and applications. The heat radiation by LPG pool fires poses hazards to individuals nearby and can lead to potential failures of ambient facilities. Due to the high costs and invasive nature of experiments for investigating largescale pool fires, computational fluid dynamics (CFD) is employed in this study as the cost-effective and noninvasive method to simulate the process and analyze the characteristics of large hydrocarbon pool fires. Specifically, an experimentally validated 3-D CFD model has been built to simulate surface emissive power (SEP) and incident radiation of large-scale LPG pool fires with three different diameters and wind speeds. Steady-state simulations with P1 radiation and probability density function (PDF) combustion models were employed to obtain reliable data after the optimizations based on the comparisons with experimental data and empirical models. The comparison with benchmark experimental data demonstrates that the CFD model employed in this study can accurately predict the incident radiation of large LPG pool fires. A new SEP correlation is also proposed, which is specifically for LPG pool fires with a diameter between 10 m and 20 m. Additionally, the safe separation distances between LPG facilities and surrounded objects have been estimated based on the CFD simulation results. The high-resolution CFD model for large LPG pool fires in this work provides noninvasive and direct quantitative evidence to enhance the fundamental understanding on the safety of large LPG pool fires and can assist regulatory agencies in refining the safety limits in the cost-effective and time-saving manners.
Mathematical Modelling and Simulation of Heat Dispersion Due to Fire and Explosion
Jurnal Teknologi, 2002
Fire and explosion are among the commonly occurring major hazards in the operation of chemical plants. In this paper, a mathematical model for heat dispersion in the event of an industrial fire and explosion is presented. The model is simulated numerically within MATLAB environment to provide both the time and space dependence of the heat flux and temperature using a finite difference method. Three classes of fire were considered. These are pool fire, flash fire and fireball following the event of Boiling Liquid Expanding Vapour (BLEVE). The simulation program that has been developed is employed to study the impact of the three types of fire hazard on a LPG storage facility at the Chemical Engineering Pilot Plant in the Universiti Teknologi Malaysia. The results obtained highlights the various hazard condition for all the three events, with fireball imposing the most severe condition by having safety distance of 300 meters away from the source of release, within which fatalities are expected.
Prediction of Deflagrative Explosions in Variety of Closed Vessels
Energies, 2021
In this paper the multi-phenomena deflagration model is used to simulate deflagrative combustion of several fuel–air mixtures in various scale closed vessels. The experimental transient pressure of methane–air, ethane–air, and propane–air deflagrations in vessels of volume 0.02 m3, 1 m3, and 6 m3 were simulated. The model includes key mechanisms affecting propagation of premixed flame front: the dependence of laminar burning velocity of concentration, pressure, and temperature; the effect of preferential diffusion in the corrugated flame front or leading point concept; turbulence generated by flame front itself or Karlovitz turbulence; increase of the flame front area with flame radius by fractals; and turbulence in the unburned mixture. Laminar velocity dependence on concentration, pressure, and temperature were calculated using CANTERA software. Various scale and geometry of used vessels induces various combustion mechanism. Simulations allow insight into the dominating mechanism....
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Hazards from the fireball and blast wave after high-pressure hydrogen tank rupture in a fire are not yet fully understood. The contemporary tools like CFD are not yet validated against experimental data to be used as a reliable predictive tool for such catastrophic failures. In this study the experiment with high-pressure hydrogen storage tank rupture in a fire, followed by a blast wave and a fireball, was numerically simulated. The applied CFD model includes the eddy dissipation concept (EDC) sub-model for combustion incorporating a detailed chemistry with 37 chemical reactions, and the RNG k-epsilon sub-model for turbulence. The model has been recently successfully applied to simulate experimental data on spontaneous ignition of hydrogen during the sudden release into the air, and different indoor jet fire regimes. In this study, the results of the simulations are compared against experimental data on a high-pressure (35 MPa) stand-alone hydrogen tank of volume 72.4 l rupture in a...
Hazard of Pressurized Tanks Involved in Fires
Industrial & Engineering Chemistry Research, 2003
Tanks devoted to the storage and transportation of liquefied petroleum gases (LPGs) are exposed to serious hazards when involved in a fire. Under particular conditions, the boiling liquid expanding vapor explosion (BLEVE) can occur with catastrophic consequences. In the present paper, a mathematical model developed to evaluate the LPG tank behavior for different fire scenarios is presented. Major hazards have been identified distinguishing, in order of gravity, among jet release, catastrophic loss of containment, i.e., the failure of the tank followed by rapid evaporation of the superheated liquid without the development of blast waves, and BLEVE. The effects of accidental cracks, of the presence of a pressure safety valve, and of an insulating layer have been investigated as well. Eventually, the severity of the fireball, of the blast wave, or of the fragments produced by the BLEVE has been assessed as a function of both the scenario and the thermal condition of the containment at the moment of failure.
Simulation of Propane Explosion in Closed Vessel
2017
Dust and gas explosions occur in a wide range of industrial segments. They can cause significant harms, when they happen in closed areas, like industrial enclosures, vessels, pipelines, elevators, etc. Evaluation of the possible size of harms based on explosibility of substances, maximum explosion overpressures and maximum pressure rises. Exact measurements in industrial enclosures are greatly dangerous, because load bearing capacity of equipment is finite, and in case of any damage needed to grant proper safety for living beings and environment. Totally explosion-proof enclosures are used mainly in laboratories, which are proper for specifying explosion characteristics of different materials. This article investigates propane explosions in a closed spherical vessel based on experimental and simulation data. The vessel was a 20-liter spherical explosion chamber by Kühner, and5 vol. % propane-air mixtures were investigated in it. A numerical model was elaborated to simulate concentra...
Process Safety and Environmental Protection, 2019
Fire Dynamics Simulator (FDS) is used to simulate tank and dike fires in a tank farm. FDS is compared to experimental data of 1 m crude oil pool fire and 30 m and 50 m diameter kerosene pool fires. A good agreement was found between the results of three experiments and the FDS predictions. Potential for secondary fire events in nearby storage tanks is evaluated based on the resulting incident radiative heat flux.
A Large Eddy Simulation of LNG Pool Fire on Board a Chemical/Oil Tanker
Journal of Physics: Conference Series
The air pollution from maritime transportation has become one of the major environmental concerns. The liquefied natural gas (LNG) has better environmental performance compared to conventional ship fuels. Therefore, the use of LNG as ship fuel has recently gained more attention in the maritime industry. On the other hand, LNG as a fuel can have high risks of explosion and fire on ships. Among the various LNG ship fires, the pool fire is the most common phenomenon. Therefore, this study focuses on the LNG pool fire on board a chemical/oil tanker with different pool aspect ratios. Also, the effects of wind speed on the flame characteristics are investigated. The LNG pool fire on board a chemical/oil tanker is studied by using large eddy simulation approach and Fire Dynamic Simulator (FDS) code, numerically. The results show that the flame characteristics are affected markedly by the pool aspect ratio and wind speed. While the aspect ratio increases, the mean flame height reduces, whereas the heat flux values increases. It is also found that the heat flux values increase with the wind speed.
CFD Analysis of Hydrocarbon Fireballs
Combustion Science and Technology, 2017
3D Computational Fluid Dynamics (CFD) simulations of hydrocarbon fireballs have been performed for their detailed characterization including diameter, lifetime, flame and internal fireball structure. The diameter and duration of fireball obtained by CFD simulations and available empirical models have been compared with experiments and video footage data.. CFD simulations are essential as empirical models have inherent assumptions and limitation in describing internal fireball structures. The fireball resulting from the loss of fuel tank exposed to fire (experiment conducted by the German Bundesanstalt für Materialforschung (BAM) in 1999) and a fireball from an aircraft crash (aircraft ambulance crash in Iceland in 2013) are considered for the CFD analysis. Influence of initial momentum, turbulence and radiation on fireball structure has been analyzed for both the cases. To illustrate transient behavior, developed pressure and flame structures are studied during the evolution of fireball.. Fireball diameter and lifting height computed from numerical analysis is found in good agreement with available video footage data. The incident radiations on ground are calculated using numerical method along the radial position from the center of fireball, to predict the thermal hazards from the fireball.